Living Reviews in Relativity
Living Reviews in Relativity is a peer-reviewed, open-access journal publishing invited reviews on all areas of relativity research. Articles are regularly updated by their authors. All reference information is collected in a free online database.
physics, astrophysics, mathematics, astrophysics, relativity, Einstein, review articles
http://relativity.livingreviews.org/
1433-8351
en
Springer International Publishing AG
copyright Springer International Publishing AG
journal
2016-10-04
stachel.john
Theoretical physics (primarily general relativity, as well as quantum gravity), philosophy and history of science
Center for Einstein Studies, Boston University, 745 Commonwealth Avenue, Boston, MA 02215, U.S.A.
John Stachel
author
Stachel
John
2005-02-21
lrr-2005-2
The main purpose of this article is to provide a guide to theorems on global properties of solutions to the Einstein-Vlasov system. This system couples Einstein’s equations to a kinetic matter model. Kinetic theory has been an important field of research during several decades in which the main focus has been on nonrelativistic and special relativistic physics, i.e. to model the dynamics of neutral gases, plasmas, and Newtonian self-gravitating systems. In 1990, Rendall and Rein initiated a mathematical study of the Einstein-Vlasov system. Since then many theorems on global properties of solutions to this system have been established. The Vlasov equation describes matter phenomenologically, and it should be stressed that most of the theorems presented in this article are not presently known for other such matter models (i.e. fluid models). This paper gives introductions to kinetic theory in non-curved spacetimes and then the Einstein-Vlasov system is introduced. We believe that a good understanding of kinetic theory in non-curved spacetimes is fundamental to good comprehension of kinetic theory in general relativity.
The Einstein-Vlasov System/Kinetic Theory
2005LRR.....8....2A
2
2005-02-23
2005-03-18
Updated and extended article: Sections 1.3 and 2.3 added, extended reference list from previous 90 to 121.
8
publication
lrr-2010-3
f(R) Theories
2010-02-26
2010LRR....13....3D
Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity – such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans–Dicke theory and Gauss–Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.
3
2010-05-17
2010-06-23
13
inflation
f(R) gravity
modified gravity
dark energy
cosmological perturbations
publication
lrr-2013-7-larson.shane
authorOrder
3
liberati.stefano
International School for Advanced Studies and INFN, Via Beirut 2-4, 34014 Trieste, Italy
Stefano Liberati
author
Liberati
Stefano
sperhake.ulrich
General relativity, Black hole simulations
DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, U.K.
Ulrich Sperhake
author
Sperhake
Ulrich
abbott-benjamin
California Institute of Technology, Pasadena, U.S.A.
Benjamin P. Abbott
author
Abbott
Benjamin P.
2015-07-21
Extraction of gravitational waves in numerical relativity
A numerical-relativity calculation yields in general a solution of the Einstein equations including also a radiative part, which is in practice computed in a region of finite extent. Since gravitational radiation is properly defined only at null infinity and in an appropriate coordinate system, the accurate estimation of the emitted gravitational waves represents an old and non-trivial problem in numerical relativity. A number of methods have been developed over the years to “extract” the radiative part of the solution from a numerical simulation and these include: quadrupole formulas, gauge-invariant metric perturbations, Weyl scalars, and characteristic extraction. We review and discuss each method, in terms of both its theoretical background as well as its implementation. Finally, we provide a brief comparison of the various methods in terms of their inherent advantages and disadvantages.
2
2016-06-27
2016-10-04
lrr-2016-2
19
Binary mergers
Gravitational wave extraction
Black holes
Neutron stars
Numerical relativity
publication
lrr-2005-1
Quantum Gravity in 2+1 Dimensions: The Case of a Closed Universe
2005LRR.....8....1C
In three spacetime dimensions, general relativity drastically simplifies, becoming a ``topological'' theory with no propagating local degrees of freedom. Nevertheless, many of the difficult conceptual problems of quantizing gravity are still present. In this review, I summarize the rather large body of work that has gone towards quantizing (2+1)-dimensional vacuum gravity in the setting of a spatially closed universe.
1
2004-12-07
2005-01-24
8
quantum cosmology
quantum gravity
2+1 gravity
publication
lrr-2004-1
The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, "conformal infinity" is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation, and how it lends itself very naturally to the solution of radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.
Conformal Infinity
7
2004LRR.....7....1F
1
2004-01-23
2004-02-02
Sections 3.4, 3.5, 4.2, 4.3, 4.5 and the appendix have been updated. Reference list has been expanded from 148 to 166 entries.
publication
lrr-2014-7
Massive Gravity
2014-01-06
2014LRR....17....7D
We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware–Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alternative and related models of massive gravity such as new massive gravity, Lorentz-violating massive gravity and non-local massive gravity.
7
2014-07-18
2014-08-25
17
General relativity, Gravity, Alternative theories of gravity, Modified theories of gravity, Massive gravity
publication
lrr-2012-1-adamo.timothy
authorOrder
1
krolak.andrzej
My field is application of mathematical methods to general theory of relativity.
Institute of Mathematics, Polish Academy of Sciences, Śniadeckich 8, 00-950 Warsaw, Poland
Andrzej Królak
author
Królak
Andrzej
khalili.farid
Quantum Measurement Theory
Faculty of Physics, Moscow State University, Moscow 119991, Russia
Farid Ya. Khalili
author
Khalili
Farid Ya.
lrr-2013-2
Minimal Length Scale Scenarios for Quantum Gravity
2012-03-28
2013LRR....16....2H
We review the question of whether the fundamental laws of nature limit our ability to probe arbitrarily short distances. First, we examine what insights can be gained from thought experiments for probes of shortest distances, and summarize what can be learned from different approaches to a theory of quantum gravity. Then we discuss some models that have been developed to implement a minimal length scale in quantum mechanics and quantum field theory. These models have entered the literature as the generalized uncertainty principle or the modified dispersion relation, and have allowed the study of the effects of a minimal length scale in quantum mechanics, quantum electrodynamics, thermodynamics, black-hole physics and cosmology. Finally, we touch upon the question of ways to circumvent the manifestation of a minimal length scale in short-distance physics.
2
2012-10-11
2013-01-29
16
Minimal length
Generalized uncertainty principle
Quantum gravity
publication
wambsganss.joachim
The main scientific topics interests are gravitational lensing, clusters of galaxies and extrasolar planets.
Astronomisches Rechen-Institut (ARI), Mönchhofstr. 12-14, D-69120 Heidelberg, Germany
799
Joachim Wambsganss
author
Wambsganss
Joachim
lrr-2009-3
I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to eliminate the role of this artificial outer boundary via Cauchy-characteristic matching, by which the radiated waveform can be computed at null infinity. Progress in this direction is discussed.
Characteristic Evolution and Matching
2009LRR....12....3W
3
2009-04-09
2008-10-08
2009-04-16
Significantly updated previous version. About 30 references have been added. The text has been revised at several points. Added new Sections 4, 5.3 and 6.
12
Characteristic initial value problem
Numerical methods
Numerical relativity
publication
tsujikawa.shinji
In particular I am interested in research areas related to cosmology and gravitation such as: Inflationary Universe, Particle creations in early universe, String Cosmology, Cosmological density perturbations, Cosmic microwave background and large scale structure, Dark energy, Loop quantum gravity, Modified gravity, Black holes, and Neutrino Physics
Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
Shinji Tsujikawa
author
Tsujikawa
Shinji
lrr-2012-9
Continuum and Discrete Initial-Boundary Value Problems and Einstein's Field Equations
2011-04-04
2012LRR....15....9S
Many evolution problems in physics are described by partial differential equations on an infinite domain; therefore, one is interested in the solutions to such problems for a given initial dataset. A prominent example is the binary black-hole problem within Einstein's theory of gravitation, in which one computes the gravitational radiation emitted from the inspiral of the two black holes, merger and ringdown. Powerful mathematical tools can be used to establish qualitative statements about the solutions, such as their existence, uniqueness, continuous dependence on the initial data, or their asymptotic behavior over large time scales. However, one is often interested in computing the solution itself, and unless the partial differential equation is very simple, or the initial data possesses a high degree of symmetry, this computation requires approximation by numerical discretization. When solving such discrete problems on a machine, one is faced with a finite limit to computational resources, which leads to the replacement of the infinite continuum domain with a finite computer grid. This, in turn, leads to a discrete initial-boundary value problem. The hope is to recover, with high accuracy, the exact solution in the limit where the grid spacing converges to zero with the boundary being pushed to infinity.
The goal of this article is to review some of the theory necessary to understand the continuum and discrete initial boundary-value problems arising from hyperbolic partial differential equations and to discuss its applications to numerical relativity; in particular, we present well-posed initial and initial-boundary value formulations of Einstein's equations, and we discuss multi-domain high-order finite difference and spectral methods to solve them.
9
2012-05-02
2012-08-27
15
Partial differential equations
Boundary value problems
publication
koyama.kazuya
Institute of Cosmology & Gravitation, University of Portsmouth, Portsmouth PO1 3FX, U.K.
Kazuya Koyama
author
Koyama
Kazuya
lrr-2001-5
We review the properties and applications of binary and millisecond pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1300. There are now 56 binary and millisecond pulsars in the Galactic disk and a further 47 in globular clusters. This review is concerned primarily with the results and spin-offs from these surveys which are of particular interest to the relativity community.
Binary and Millisecond Pulsars at the New Millennium
2001LRR.....4....5L
5
2001-04-20
2001-06-18
Article revision based on recent developments (observed pulsar population has almost doubled); appendix with tables of parameters of binary and millisecond pulsars has been added.
4
pulsars
publication
lrr-1999-3
Numerical Hydrodynamics in Special Relativity
This review is concerned with a discussion of numerical methods for the solution of the equations of special relativistic hydrodynamics (SRHD). Particular emphasis is put on a comprehensive review of the application of high-resolution shock-capturing methods in SRHD. Results obtained with different numerical SRHD methods are compared, and two astrophysical applications of SRHD flows are discussed. An evaluation of the various numerical methods is given and future developments are analyzed.
3
1999-11-10
1999-12-15
2
publication
lrr-2000-3
Gravitational Wave Detection by Interferometry (Ground and Space)
2000LRR.....3....3H
Significant progress has been made in recent years on the development of gravitational wave detectors. Sources such as coalescing compact binary systems, low-mass X-ray binaries, stellar collapses and pulsars are all possible candidates for detection. The most promising design of gravitational wave detector uses test masses a long distance apart and freely suspended as pendulums on Earth or in drag-free craft in space. The main theme of this review is a discussion of the mechanical and optical principles used in the various long baseline systems being built around the world -- LIGO (USA), VIRGO (Italy/France), TAMA 300 (Japan) and GEO 600 (Germany/UK) -- and in LISA, a proposed space-borne interferometer.
3
2000-01-24
2000-06-29
3
gravitational waves
laser interferometry
publication
bern.zvi
Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, CA 90095, U.S.A.
900
Zvi Bern
author
Bern
Zvi
larson.shane
Center for Interdisclipinary Research and Exploration in Astrophysics, Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA
Shane L. Larson
author
Larson
Shane L.
sumner.timothy
Direct dark matter searches and gravitational physics measurements using space missions.
Astrophysics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BZ, U.K.
654
Timothy J. Sumner
author
Sumner
Timothy J.
kokkotas.kostas
My research is related to the study of gravitational waves sources. My speciality is the study of dynamics and stability of neutron stars and black holes.
Institute for Astronomy and Astrophysics (IAAT) of the Eberhard-Karls-University Tübingen, D-72076 Tübingen, Auf der Morgenstelle 10, Germany
218
Kostas D. Kokkotas
author
Kokkotas
Kostas D.
lrr-2015-3
Terrestrial Gravity Fluctuations
2015-07-21
2015LRR....18....3H
Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10^–23 Hz^–1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of terrestrial gravity fluctuations will have great impact on the future development of GW detectors and high-precision gravimetry in general, and many open questions need to be answered still as emphasized in this article.
3
2015-11-16
2015-12-02
18
Terrestrial gravity
Wiener filter
Mitigation
Newtonian noise
publication
reall.harvey
General relativity and string theory.
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
Harvey S. Reall
author
Reall
Harvey S.
lrr-2009-6-u1
2010-06-23
2010-06-25
The two major changes are the addition of Appendix D, and that we have rewritten about a quarter of Section 7. The extra appendix was just to add new information while the changes in Section 7 were due to real errors on our part. In addition there were many very small changes, words changed here and there; a few small paragraphs were added as well. These word changes were needed to correct the errors (mainly language) in Section 7. Several misprints were also corrected and a new reference to Adamo and Newman (2010) was added.
update
String
subjectField
9
String Theory and Gravitation
lrr-2001-3
I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to current 3D codes that simulate binary black holes. A prime application of characteristic evolution is Cauchy-characteristic matching, which is also reviewed.
Characteristic Evolution and Matching
2001LRR.....4....3W
3
2001-02-15
2001-03-20
Article revision adding figures and information on the use of 3D characteristic codes to simulate black holes and the use of light cone coordinates in general relativistic astrophysics.
4
publication
de-felice.antonio
Dark energy, Scalar Tensor Theories and Modified Gravity Models
Yukawa Institute for Theoretical Physics (YITP), Kyoto University, Kyoto, Japan
Antonio De Felice
author
De Felice
Antonio
lrr-2002-3-u1
2005-06-06
2005-06-27
update
lrr-2004-10
Isolated and Dynamical Horizons and Their Applications
2004LRR.....7...10A
Over the past three decades, black holes have played an important role in quantum gravity, mathematical physics, numerical relativity and gravitational wave phenomenology. However, conceptual settings and mathematical models used to discuss them have varied considerably from one area to another. Over the last five years a new, quasi-local framework was introduced to analyze diverse facets of black holes in a unified manner. In this framework, evolving black holes are modelled by dynamical horizons and black holes in equilibrium by isolated horizons. We review basic properties of these horizons and summarize applications to mathematical physics, numerical relativity, and quantum gravity. This paradigm has led to significant generalizations of several results in black hole physics. Specifically, it has introduced a more physical setting for black hole thermodynamics and for black hole entropy calculations in quantum gravity, suggested a phenomenological model for hairy black holes, provided novel techniques to extract physics from numerical simulations, and led to new laws governing the dynamics of black holes in exact general relativity.
10
2004-11-23
2004-12-15
7
quantum gravity
generalized thermodynamics
black holes
publication
gundlach.carsten
Simulations of core collapse and binary neutron star mergers; Formulations of the Einstein equations, boundary conditions, and gauge choices for numerical relativity; Effects of rotation and magnetic fields in gravitational collapse
Faculty of Mathematical Studies, University of Southampton, Highfield, Southampton SO17 1BJ, U.K.
821
Carsten Gundlach
author
Gundlach
Carsten
lrr-2002-4
Experimental Searches for Dark Matter
2002LRR.....5....4S
There is now an enormously rich variety of experimental techniques being brought to bear on experimental searches for dark matter, covering a wide range of suggested forms for it. The existence of "dark matter", in some form or other, is inferred from a number of relatively simple observations and the problem has been known for over half a century. To explain "dark matter" is one of the foremost challenges today -- the answer will be of fundamental importance to cosmologists, astrophysicists, particle physicists, and general relativists. In this article, I will give a brief review of the observational evidence (concentrating on areas of current significant activity), followed by an equally brief summary of candidate solutions for the 'dark matter'. I will then discuss experimental searches, both direct and indirect. Finally, I will offer prospects for the future.
4
2002-04-16
2002-07-23
5
experimental dark matter search
publication
isham
Imperial College London, UK
Chris Isham
ebMember
isham
Isham
Chris
lrr-2013-7-gair.jonathan
authorOrder
1
danilishin.stefan
School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley 6009, Australia and Faculty of Physics, Moscow State University, Moscow 119991, Russia
Stefan L. Danilishin
author
Danilishin
Stefan L.
lrr-2002-7
The Einstein-Vlasov System/Kinetic Theory
2002LRR.....5....7A
The main purpose of this article is to provide a guide to theorems on global properties of solutions to the Einstein-Vlasov system. This system couples Einstein's equations to a kinetic matter model. Kinetic theory has been an important field of research during several decades in which the main focus has been on nonrelativistic and special relativistic physics, i.e., to model the dynamics of neutral gases, plasmas, and Newtonian self-gravitating systems. In 1990, Rendall and Rein initiated a mathematical study of the Einstein-Vlasov system. Since then many theorems on global properties of solutions to this system have been established. The Vlasov equation describes matter phenomenologically, and it should be stressed that most of the theorems presented in this article are not presently known for other such matter models (i.e., fluid models). This paper gives introductions to kinetic theory in non-curved spacetimes and then the Einstein-Vlasov system is introduced. We believe that a good understanding of kinetic theory in non-curved spacetimes is fundamental to good comprehension of kinetic theory in general relativity.
7
2002-10-18
2002-12-06
5
publication
solodukhin.sergey
General relativity, theoretical high-energy physics as applied to black holes and cosmology. In recent years my work has focused on the development of the conformal field theory description of black hole phenomena, the study of information loss in black holes, the exploration of observable implications of extra dimensions, and the formulation of the holographic description in curved and flat space-times.
Laboratoire de Mathématiques et Physique Théorique, Université François-Rabelais Tours Fédération Denis Poisson - CNRS, Parc de Grandmont, 37200 Tours, France
Sergey N. Solodukhin
author
Solodukhin
Sergey N.
renn
MPI for the History of Science, Germany
Jürgen Renn
ebMember
renn
Renn
Jürgen
amelino-camelia.giovanni
Quantum gravity
Dipart. Fisica Univ. La Sapienza and Sez. Roma1 INFN, P.le Moro 2, I-00185 Roma, Italy
Giovanni Amelino-Camelia
author
Amelino-Camelia
Giovanni
simon.joan
His research interests lie in the understanding of the structure of space and time, using the study of black holes and cosmological singularities in the framework of string theory, and the possible observational signatures that this theory may have in experiments.
School of Mathematics, The University of Edinburgh, and Maxwell Institute for Mathematical Sciences, Edinburgh EH9 3JZ, U.K.
Joan Simón
author
Simón
Joan
lrr-2005-5
Modern Tests of Lorentz Invariance
2005-06-09
2005LRR.....8....5M
Motivated by ideas about quantum gravity, a tremendous amount of effort over the past decade has gone into testing Lorentz invariance in various regimes. This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible. The current constraints on Lorentz violating effects from both terrestrial experiments and astrophysical observations are presented.
5
2005-07-04
2005-09-07
8
Lorentz invariance, Quantum gravity phenomenology
publication
lrr-1998-8
Rotating Stars in Relativity
Because of the information they can yield about the equation of state of matter at extremely high densities and because they are one of the more possible sources of detectable gravitational waves, rotating relativistic stars have been receiving significant attention in recentyears. We review the latest theoretical and numerical methods for modeling rotating relativistic stars, including stars with a strong magnetic field and hot proto-neutron stars. We also review nonaxisymmetric oscillations and instabilities in rotating stars and summarize the latest developments regarding the gravitational wave-driven (CFS) instability in both polar and axial quasi-normal modes.
8
1998-05-28
1998-06-18
1
relativistic stars
gravitational wave sources
neutron stars
pulsars
publication
lrr-2008-10
Physics of Neutron Star Crusts
2008-06-20
2008LRR....11...10C
The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.
10
2008-09-05
2008-12-12
11
astrophysics, neutron stars, pulsars, magnetars, soft gamma repeaters, supernova, elasticity, neutron star cooling, low-mass X-ray binaries, oscillations, structure, transport properties, conductivity, viscosity, neutrino, equation of state, neutron star crust, superfluidity, entrainment, two-fluid model, accretion, X-ray astronomy, gravitational waves, pulsar glitches, accreting neutron stars, deep crustal heating
publication
barcelo.carlos
Instituto de Astrofísica de Andalucía (CSIC), Camino Bajo de Huetor 50, 18008 Granada, Spain
Carlos Barceló
author
Barceló
Carlos
lrr-1998-7
Numerical Approaches to Spacetime Singularities
This review updates a previous review article. Numerical explorationof the properties of singularities could, in principle, yield detailed understanding of their nature in physically realistic cases. Examples of numerical investigations into the formation of naked singularities, critical behavior in collapse, passage through the Cauchy horizon, chaos of the Mixmaster singularity, and singularities in spatially inhomogeneous cosmologies are discussed.
7
1998-05-03
1998-05-08
1
numerical relativity
singularities
publication
maartens.roy
Cosmological Perturbations, Brane-World Gravity, Cosmological Dynamics
Institute of Cosmology and Gravitation, Portsmouth University, Portsmouth PO12EG, U.K.
244
Roy Maartens
author
Maartens
Roy
lrr-1999-4
Critical Phenomena in Gravitational Collapse
1999LRR.....2....4G
As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term "critical phenomena". They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. This review gives an introduction to the phenomena, tries to summarize the essential features of what is happening, and then presents extensions and applications of this basic scenario. Critical phenomena are of interest particularly for creating surprising structure from simple equations, and for the light they throw on cosmic censorship and the generic dynamics of general relativity.
4
1999-12-07
1999-12-22
2
publication
lrr-2009-5
On Special Optical Modes and Thermal Issues in Advanced Gravitational Wave Interferometric Detectors
2008-07-10
2009LRR....12....5V
The sensitivity of present ground-based gravitational wave antennas is too low to detect many events per year. It has, therefore, been planned for years to build advanced detectors allowing actual astrophysical observations and investigations. In such advanced detectors, one major issue is to increase the laser power in order to reduce shot noise. However, this is useless if the thermal noise remains at the current level in the 100 Hz spectral region, where mirrors are the main contributors. Moreover, increasing the laser power gives rise to various spurious thermal effects in the same mirrors. The main goal of the present study is to discuss these issues versus the transverse structure of the readout beam, in order to allow comparison. A number of theoretical studies and experiments have been carried out, regarding thermal noise and thermal effects. We do not discuss experimental problems, but rather focus on some theoretical results in this context about arbitrary order Laguerre–Gauss beams, and other “exotic” beams.
5
2009-05-14
2009-07-17
12
Optics
Gravitational radiation
Gravitational wave detectors
Interferometry
publication
lrr-2003-4
The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article, the present update provides additional information on numerical schemes, and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes, and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.
Numerical Hydrodynamics in General Relativity
2003LRR.....6....4F
4
2003-05-06
2003-08-19
Article revision. Sections 3 and 4 have undergone substantial changes and have been considerably enlarged; almost all sections have been updated. The number of references has been extended from previous 241 to the current 319.
6
publication
lrr-2003-2
Gravitational Waves from Gravitational Collapse
2003LRR.....6....2N
Gravitational wave emission from stellar collapse has been studied for more than three decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars.
2
2003-01-13
2003-03-10
6
gravitational wave sources
gravitational collapse
publication
dettwyler
Copy Editor (2008-2014)
Miranda Dettwyler
teamMember
c
Dettwyler
Miranda
PhysCosmol
subjectField
6
Physical Cosmology
hossenfelder.sabine
My main research area is the phenomenology of physics beyond the standard model and quantum gravity.
Nordita, Roslagstullsbacken 23, 106 91 Stockholm, Sweden
Sabine Hossenfelder
author
Hossenfelder
Sabine
lrr-2003-1-u1
2007-06-11
2007-06-21
Two sections near the end were added; one on Augmentation systems, and one on Global Navigation Systems. General updating: I have updated the text in quite a few places, such as eliminating the word “recently” which is no longer really recently. Also the Conclusion has been appropriately reworded. Added one reference. Living Reviews applied its current layout to this revision.
update
lrr-2007-3
Event and Apparent Horizon Finders for 3+1 Numerical Relativity
2007-04-10
2007LRR....10....3T
Event and apparent horizons are key diagnostics for the presence and properties of black holes. In this article I review numerical algorithms and codes for finding event and apparent horizons in numerically-computed spacetimes, focusing on calculations done using the 3+1 ADM formalism. The event horizon of an asymptotically-flat spacetime is the boundary between those events from which a future-pointing null geodesic can reach future null infinity and those events from which no such geodesic exists. The event horizon is a (continuous) null surface in spacetime. The event horizon is defined nonlocally in time: it is a global property of the entire spacetime and must be found in a separate post-processing phase after all (or at least the nonstationary part) of spacetime has been numerically computed.
There are three basic algorithms for finding event horizons, based on integrating null geodesics forwards in time, integrating null geodesics backwards in time, and integrating null surfaces backwards in time. The last of these is generally the most efficient and accurate.
In contrast to an event horizon, an apparent horizon is defined locally in time in a spacelike slice and depends only on data in that slice, so it can be (and usually is) found during the numerical computation of a spacetime. A marginally outer trapped surface (MOTS) in a slice is a smooth closed 2-surface whose future-pointing outgoing null geodesics have zero expansion Theta. An apparent horizon is then defined as a MOTS not contained in any other MOTS. The MOTS condition is a nonlinear elliptic partial differential equation (PDE) for the surface shape, containing the ADM 3-metric, its spatial derivatives, and the extrinsic curvature as coefficients. Most “apparent horizon” finders actually find MOTSs.
There are a large number of apparent horizon finding algorithms, with differing trade-offs between speed, robustness, accuracy, and ease of programming. In axisymmetry, shooting algorithms work well and are fairly easy to program. In slices with no continuous symmetries, spectral integral-iteration algorithms and elliptic-PDE algorithms are fast and accurate, but require good initial guesses to converge. In many cases, Schnetter’s “pretracking” algorithm can greatly improve an elliptic-PDE algorithm’s robustness. Flow algorithms are generally quite slow but can be very robust in their convergence. Minimization methods are slow and relatively inaccurate in the context of a finite differencing simulation, but in a spectral code they can be relatively faster and more robust.
3
2007-04-17
2007-06-01
10
trapped surfaces
numerical relativity
null surfaces
numerical algorithms
partial differential equations
event horizons
apparent horizons
black holes
ADM formalism
publication
plefka.jan
Theoretical high energy and gravitational physics, in particular string theory, quantum field theory, supersymmetry and supergravity, supermembranes, matrix models and gauge field theory.
Humboldt Universität zu Berlin, Institut für Physik, Newtonstrasse 15, D-12489 Berlin, Germany
Jan Plefka
author
Plefka
Jan
sarbach.olivier
Einstein's equations, stability of compact objects, numerical analysis
Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, 58040 Morelia, Michoacán, Mexico
Olivier Sarbach
author
Sarbach
Olivier
lrr-2001-6
The Thermodynamics of Black Holes
2001LRR.....4....6W
We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.
6
2001-02-13
2001-07-09
4
Euclidean methods
quantum gravity
variational methods
Killing horizons
generalized second law
thermodynamics
entropy bounds
statistical mechanics
quantum field theory
Hawking radiation
black hole thermodynamics
event horizons
black holes
publication
wobst
ePublishing Toolkit Programming & Server Admin (2005-2011)
André Wobst
f
Wobst
teamMember
lrr-2011-8
Entanglement Entropy of Black Holes
2011-04-18
2011LRR....14....8S
The entanglement entropy is a fundamental quantity, which characterizes the correlations between sub-systems in a larger quantum-mechanical system. For two sub-systems separated by a surface the entanglement entropy is proportional to the area of the surface and depends on the UV cutoff, which regulates the short-distance correlations. The geometrical nature of entanglement-entropy calculation is particularly intriguing when applied to black holes when the entangling surface is the black-hole horizon. I review a variety of aspects of this calculation: the useful mathematical tools such as the geometry of spaces with conical singularities and the heat kernel method, the UV divergences in the entropy and their renormalization, the logarithmic terms in the entanglement entropy in four and six dimensions and their relation to the conformal anomalies. The focus in the review is on the systematic use of the conical singularity method. The relations to other known approaches such as 't Hooft's brick-wall model and the Euclidean path integral in the optical metric are discussed in detail. The puzzling behavior of the entanglement entropy due to fields, which non-minimally couple to gravity, is emphasized. The holographic description of the entanglement entropy of the black-hole horizon is illustrated on the two- and four-dimensional examples. Finally, I examine the possibility to interpret the Bekenstein-Hawking entropy entirely as the entanglement entropy.
8
2011-08-23
2011-10-21
14
Bekenstein-Hawking entropy
entanglement entropy
black holes
publication
lrr-1998-4
Local and Global Existence Theorems for the Einstein Equations
This article is a guide to the literature on existence theorems for the Einstein equations which also draws attention to open problems in the field. The local in time Cauchy problem, which is relatively well understood, is treated first. Next global results for solutionswith symmetry are discussed. This is followed by a presentation of global results in the case of small data, and some miscellaneous topics connected with the main theme.
4
1998-01-15
1998-01-26
1
publication
famaey.benoit
Galactic kinematics and dynamics, Non-axisymmetries and moving groups, Streaming motions and radial migrations, The missing mass (or missing gravity) problem
Observatoire Astronomique de Strasbourg, CNRS, UMR 7550, France and AIfA, University of Bonn, Germany
Benoît Famaey
author
Famaey
Benoît
marti.jose
Departamento de Astronomía y Astrofísica, Universidad de Valencia, 46100 Burjassot (Valencia), Spain
793
José Maria Martí
author
Martí
José Maria
wambsganss
Heidelberg University, Germany
Joachim Wambsganss
ebMember
wambsganss
Wambsganss
J.
lrr-2000-3-hough.jim
authorOrder
2
lrr-2011-1
Gravitational-wave emission from stellar collapse has been studied for nearly four decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion-induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars.
Gravitational Waves from Gravitational Collapse
2011LRR....14....1F
1
2011-01-14
2010-06-19
2011-01-20
We have significantly altered and restructured the text of the previous version, describing the latest results from a new point of view. New figures have been added. The number of references has increased from 271 to 351.
14
Gravitational wave sources
Gravitational collapse
publication
suto.yasushi
Theoretical cosmology. Specific examples include theory of structure formation in the universe, modeling galaxy clusters on the basis of multi-band observations, gravitational lens astronomy, cosmological hydrodynamic simulations, galaxy evolution model using the Monte-Carlo method, nonlinear gravitational many-body problems, general relativistic effects at high redshift universes, origin of biasing of astronomical objects relative to dark matter distribution, and search for extrasolar planets.
Department of Physics and Research Center for the Early Universe, The University of Tokyo, Tokyo 113-0033, Japan
972
Yasushi Suto
author
Suto
Yasushi
lrr-2001-2u1
2004-12-09
2005-04-14
Fast-track revision to include recent developments. 37 new references have been added.
update
lrr-2013-7
Testing General Relativity with Low-Frequency, Space-Based Gravitational-Wave Detectors
2012-12-13
2013LRR....16....7G
We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ∼ 10^{-5} – 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of propagation of gravitational waves; the binding energy and gravitational-wave radiation of binaries, and therefore the time evolution of binary inspirals; the strength and shape of the waves emitted from binary mergers and ringdowns; the true nature of astrophysical black holes; and much more. The strength of this science alone calls for the swift implementation of a space-based detector; the remarkable richness of astrophysics, astronomy, and cosmology in the low-frequency gravitational-wave band make the case even stronger.
7
2013-08-19
2013-09-12
16
gravitational waves
gravitation
general relativity
data analysis
eLISA
LISA
black holes
publication
HistRel
subjectField
3
History of Relativity
schulz
Manager BackOffice
Frank Schulz
teamMember
a
Schulz
Frank
lrr-2004-7
Brane-World Gravity
2004LRR.....7....7M
The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+$d$-dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the $d$ extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak ($\sim$TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. General relativity cannot describe gravity at high enough energies and must be replaced by a quantum gravity theory, picking up significant corrections as the fundamental energy scale is approached. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review discusses the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models.
7
2004-04-29
2004-06-21
7
publication
lrr-2006-1-u1
2008-01-10
2008-01-15
Included three way in Table 1; modified Figure 9 (parallel structure with Figure 12) and corrected typographical error regarding correct factor to isolate dispersive plasma in Section 4.2; updated the propagation noise Figure 10; corrected entry in Table 2 for stochastic spacecraft motion; added short discussion of flyable clocks and discussion of E(t), two Figures 24 and 25 about the antenna mechanical test, and five references; changed title of Section 8 to include “LISA”, updated throughout estimate of launch date.
update
lrr-2007-2
The Post-Newtonian Approximation for Relativistic Compact Binaries
2007-01-10
2007LRR....10....2F
We discuss various aspects of the post-Newtonian approximation in general relativity. After presenting the foundation based on the Newtonian limit, we show a method to derive post-Newtonian equations of motion for relativistic compact binaries based on a surface integral approach and the strong field point particle limit. As an application we derive third post-Newtonian equations of motion for relativistic compact binaries which respect the Lorentz invariance in the post-Newtonian perturbative sense, admit a conserved energy, and are free from any ambiguity.
2
2007-01-19
2007-03-12
10
post-Newtonian approximations, post-Newtonian expansion, equations of motion, relativistic binary systems, binary dynamics
publication
niedermaier.max
Laboratoire de Mathematiques et Physique Theorique, CNRS/UMR 6083, Université de Tours, Parc de Grandmont, 37200 Tours, France
Max Niedermaier
author
Niedermaier
Max
ashby.neil
The principal emphasis of Prof. Ashby's research is on theoretical general relativity with practical applications.
Dept. of Physics, University of Colorado, Boulder, CO 80309-0390, U.S.A.
933
Neil Ashby
author
Ashby
Neil
osswald
DB Management & Editorial Assistant (2000-2014)
Vera Osswald
teamMember
b
Osswald
Vera
will.clifford
His research interests are theoretical, encompassing the observational and astrophysical implications of Einstein's general theory of relativity, including gravitational radiation, black holes, cosmology, the physics of curved spacetime, and the theoretical interpretation of experimental tests of general relativity.
Department of Physics, University of Florida, Gainesville FL 32611
431
Clifford M. Will
author
Will
Clifford M.
uzan.jean-philippe
Institut d’Astrophysique de Paris, UMR-7095 du CNRS, Université Pierre et Marie Curie, 98 bis bd Arago, 75014 Paris (France) and Department of Mathematics and Applied Mathematics, Cape Town University, Rondebosch 7701 (South Africa) and National Institute for Theoretical Physics (NITheP), Stellenbosch 7600 (South Africa)
Jean-Philippe Uzan
author
Uzan
Jean-Philippe
lrr-2008-7
This article presents a comprehensive overview of numerical hydrodynamics and magnetohydrodynamics (MHD) in general relativity. Some significant additions have been incorporated with respect to the previous two versions of this review (2000, 2003), most notably the coverage of general-relativistic MHD, a field in which remarkable activity and progress has occurred in the last few years. Correspondingly, the discussion of astrophysical simulations in general-relativistic hydrodynamics is enlarged to account for recent relevant advances, while those dealing with general-relativistic MHD are amply covered in this review for the first time. The basic outline of this article is nevertheless similar to its earlier versions, save for the addition of MHD-related issues throughout. Hence, different formulations of both the hydrodynamics and MHD equations are presented, with special mention of conservative and hyperbolic formulations well adapted to advanced numerical methods. A large sample of numerical approaches for solving such hyperbolic systems of equations is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. As previously stated, a comprehensive summary of astrophysical simulations in strong gravitational fields is also presented. These are detailed in three basic sections, namely gravitational collapse, black-hole accretion, and neutron-star evolutions; despite the boundaries, these sections may (and in fact do) overlap throughout the discussion. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances in the formulation of the gravitational field, hydrodynamics and MHD equations and the numerical methodology designed to solve them. To keep the length of this article reasonable, an effort has been made to focus on multidimensional studies, directing the interested reader to earlier versions of the review for discussions on one-dimensional works.
Numerical Hydrodynamics and Magnetohydrodynamics in General Relativity
2008LRR....11....7F
7
2008-07-21
2008-07-14
2008-09-19
The title has been changed to emphasize that numerical magnetohydrodynamics (MHD) is now also reviewed.
The abstract has been changed accordingly, regarding the MHD aspects of the new version.
The sectioning in Section 2 is unchanged, yet the contents may have seen slight updates wherever necessary.
Section 3 on MHD is entirely new.
Section 4 (which was Section 3 in the previous version) has seen changes throughout (new text and new descriptions to account for recent developments) along with new additions.
The Section 3.2.3 in the previous version of the article has been removed and some of its contents have been moved into the "going further" section (Section 4.2.3 in the updated version of the article). Section 4.3 on the magnetic field divergence-constraint is entirely new. Section 4.4. on state-of-the-art codes has undergone major changes with respect to the corresponding Section 3.3. of the previous version of the article. This section is splitted into two main subsections, each one of them devoted to describing hydrodynamical and MHD codes, respectively. Major updates have occurred in each of these subsections and two tables have been added.
Section 5 on astrophysical applications has been widely updated and enlarged to accommodate the spectacular level of activity witnessed in the field in recent years, both regarding hydrodynamics and MHD. While the basic subsectioning of this section still coincides (broadly speaking) with that of the previous version of the article, major modifications and additions have occurred throughout regarding the contents. In general, the description of one-dimensional studies has been reduced to limit the length of the article. The previous Section 4.1.2 on critical collapse has been removed. New figures and animations have been added, in particular those appearing in Figures 7, 8, 9, 11, 13, 16, and 18 (where the numbering here applies to the revised version of the article).
The reference list has been noticeably enlarged.
11
Hydrodynamics, Relativistic hydrodynamics, Numerical relativity, Magnetohydrodynamics
publication
jaranowski.piotr
Institute of Theoretical Physics, University of Białystok, Lipowa 41, 15-424 Białystok, Poland
Piotr Jaranowski
author
Jaranowski
Piotr
lrr-2013-6
Cosmology and Fundamental Physics with the Euclid Satellite
2012-08-01
2013LRR....16....6A
Euclid is a European Space Agency medium-class mission selected for launch in 2019 within the Cosmic Vision 2015-2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky.
Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis.
This review has been planned and carried out within Euclid's Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.
6
2013-06-13
2013-09-02
16
galaxy evolution
dark energy
cosmology
publication
vega.ian
Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1
Ian Vega
author
Vega
Ian
pitkin.matthew
I am currently implementing a targeted search for gravitational waves from known pulsars. My work also involves searching for gravitational wave ring-down signals from neutron star vibrational modes.
Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.
Matthew Pitkin
author
Pitkin
Matthew
gualtieri.leonardo
General Relativity and Gravitational Waves (presently my main interest), Supergravity and String Theory, Gravity as a Gauge Theory
Dipartimento di Fisica, Università di Roma “La Sapienza” & Sezione INFN Roma1, P.A. Moro 5, 00185, Roma, Italy
Leonardo Gualtieri
author
Gualtieri
Leonardo
strain.kenneth
Development of techniques in advanced interferometry for application to the detection of gravitational radiation from astrophysical sources. In particular I have been involved in the design, testing and optimisation of signal recycling systems for laser interferometers.
Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
Kenneth A. Strain
author
Strain
Kenneth A.
lrr-2011-2
Varying Constants, Gravitation and Cosmology
2010-09-28
2011LRR....14....2U
Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.
2
2011-03-23
2011-03-29
14
theoretical cosmology
general theory of gravitation
fundamental physical constants
publication
lrr-1998-3
Hyperbolic Methods for Einstein's Equations
1998LRR.....1....3R
I review evolutionary aspects of general relativity, in particular those related to the hyperbolic character of the field equations and to the applications or consequences that this property entails. I look at several approaches to obtaining symmetric hyperbolic systems of equations out of Einstein's equations by either removing some gauge freedoms from them, or by considering certain linear combinations of a subset of them.
3
1998-01-15
1998-01-26
1
initial boundary value problem
mixed systems
harmonic gauge
symmetric hyperbolic
evolution equations
initial value problem
publication
lrr-1998-13
Discrete Approaches to Quantum Gravity in Four Dimensions
1998LRR.....1...13L
The construction of a consistent theory of quantum gravity is a problem in theoretical physics that has so far defied all attempts at resolution. One ansatz to try to obtain a non-trivial quantum theory proceeds via a discretization of space-time and the Einstein action. I review here three major areas of research: gauge-theoretic approaches, both in a path-integral and a Hamiltonian formulation; quantum Regge calculus; and the method of dynamical triangulations, confining attention to work that is strictly four-dimensional, strictly discrete, and strictly quantum in nature.
13
1998-11-19
1998-12-15
1
publication
sathyaprakash
My research interests at different times have focussed on cosmology, large-scale structure, classical field theory and symmetry breaking. For the past decade I have done most of my research on sources of gravitational waves and their detection. My research group is engaged in the analysis of data from the British-German GEO 600 and American LIGO interferometric gravitational wave detectors, mainly concerned with the searches for coalescences of compact objects (i.e. neutron stars and black holes), transients from supernovae and stochastic background.
School of Physics and Astronomy, Cardiff University, Cardiff, U.K.
B.S. Sathyaprakash
author
Sathyaprakash
B.S.
lrr-2010-4
The Pioneer Anomaly
2010-01-20
2010LRR....13....4T
Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20 – 70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ∼ 6 × 10–9 Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of aP = (8.74 ± 1.33) × 10–10 m/s2. This apparent violation of the Newton’s gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.
4
2010-07-16
2010-09-01
13
Pioneer anomaly
publication
grandclement.philippe
Laboratoire Univers et Théories, UMR 8102 du C.N.R.S., Observatoire de Paris, F-92195 Meudon Cedex, France
Philippe Grandclément
author
Grandclément
Philippe
lrr-2014-3
We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.
The Evolution of Compact Binary Star Systems
2014LRR....17....3P
3
2014-03-17
2013-10-11
2014-05-05
Major revision, updated and expanded. References are updated by 2007 – early-2014 publications, some outdated items removed. The reference list now contains 887 items instead of 475. The new version of the review has 39 figures. In Section 1, stellar evolution is outlined in more detail, special attention is paid to electron-capture supernovae. More attention than before is paid to uncertainties in the estimates of the ranges of precursors of white dwarfs, neutron stars and black holes and their masses. In Section 2, a subsection (2.3) on black holes in binaries is added and an independent estimate of black-hole/neutron-star binary coalescence rate is given. In Section 3, a subsection on mass transfer between binary components is added, discussion of common envelopes is expanded. In Section 7, the discussion of a scenario for the formation of short-period binaries is appended by a more detailed description of “intermediate” stages, like post–common-envelope binaries, the discussion of properties of binary WD is expanded, the comparison of results of population synthesis calculations for close WD with observations is updated, thanks to a significant increase in the number of observed objects. A much extended comparison of expectations from scenarios for single-degenerate and double-degenerate SNe Ia (including violent mergers) is presented. In Section 8 all published information on double-degenerates with measured periods and estimates of masses of components and some subgiant + [white dwarf] systems is summarized (up to February 2014). In Section 9 more attention than previously is paid to the initial stages of mass exchange in the “white dwarf” channel of formation of AM CVn stars and to the comparison of “white dwarf” and “helium star” channels. Final stages of the evolution of AM CVn stars and SN .Ia are discussed. In Section 10 the GW-signals of detached and interacting double-degenerates are compared in more detail, as well as their detection probabilities with planned “short-arm” (eLISA) interferometer. The former section on the overlap of EM and GW-signals from AM CVn stars is deleted because of the (temporary?) cancellation of the LISA-mission.
17
Black holes
AM CVn stars
Neutron stars
Supernovae
Binary systems
White dwarfs
Gravitational-wave sources
Astrophysics
publication
perez.alejandro
Quantum Gravity
Centre de Physique Théorique Unité Mixte de Recherche (UMR 6207) du CNRS et des e Universités Aix-Marseille I, Aix-Marseille II, et du Sud Toulon-Var; laboratoire afilié a la FRUMAM (FR 2291)
Alejandro Perez
author
Perez
Alejandro
shibata.masaru
Relativistic Astrophysics and Numerical Relativity
Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
Masaru Shibata
author
Shibata
Masaru
lrr-1998-1
Loop Quantum Gravity
1998LRR.....1....1R
The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a mathematically well-defined, non-perturbative and background independent quantization of general relativity, with its conventional matter couplings. Research in loop quantum gravity today forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained are: (i) The computation of the physical spectra of geometrical quantities such as area and volume, which yields quantitative predictions on Planck-scale physics. (ii) A derivation of the Bekenstein-Hawking black hole entropy formula. (iii) An intriguing physical picture of the microstructure of quantum physical space, characterized by a polymer-like Planck scale discreteness. This discreteness emerges naturally from the quantum theory and provides a mathematically well-defined realization of Wheeler's intuition of a spacetime ``foam''. Long standing open problems within the approach (lack of a scalar product, over-completeness of the loop basis, implementation of reality conditions) have been fully solved. The weak part of the approach is the treatment of the dynamics: at present there exist several proposals, which are intensely debated. Here, I provide a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.
1
1997-12-01
1998-01-26
1
publication
lrr-2003-2-u1
2005-12-26
2006-01-24
This revision focused mostly on updating the past review and adding more movies.
update
reula.oscar
Newtonian Limit of General Relativity, Relativistic Dissipative Fluids, Symmetric Hyperbolic Systems, Boundary Conditions for General Relativity
Universidad Nacional de Córdoba, FaMAF, Ciudad Universitaria, 5000 Córdoba, Argentina
573
Oscar A. Reula
author
Reula
Oscar A.
schutz.bernard
My research has always focused on the applications of Einstein's theory of general relativity in astrophysics. I began by studying the stability and pulsation of rotating stars, mainly in order to understand neutron stars, which can spin many hundreds of times per second. Pulsating stars emit gravitational radiation, so I got interested in the problem of gravitational wave emission, especially by stars in binary systems, which are studied by post-Newtonian methods. This led to an interest in using numerical relativity to simulate the orbiting and merging of black holes in binary systems. The development of sensitive gravitational wave detectors led me to study gravitational wave data analysis in depth. This has occupied the majority of my research time in the past two decades.
School of Physics and Astronomy, Cardiff University, Cardiff, U.K. and Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam-Golm, Germany
Bernard F. Schutz
author
Schutz
Bernard F.
liebling.steven
Long Island University, Brookville, NY 11548, USA and Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
Steven L. Liebling
author
Liebling
Steven L.
lrr-2009-2
Physics, Astrophysics and Cosmology with Gravitational Waves
2008-12-09
2009LRR....12....2S
Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.
2
2009-01-29
2009-03-04
12
Gravitational wave sources
Data analysis
Gravitational wave detectors
Gravitational waves
publication
lrr-2013-9-siemens.xavier
authorOrder
2
lahav.ofer
Estimation of cosmological parameters, Reconstruction of redshift surveys, The Cosmic Microwave Background, Clustering and evolution of galaxies, Classification of galaxy spectra and images
Department of Physics and Astronomy, University of London, Gower Street, London WC1E 6BT, U.K. and Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, U.K.
966
Ofer Lahav
author
Lahav
Ofer
lrr-1998-12-u1
Section 4.2: corrected value for surface mass density.
Bibliography: corrected year of publication in Reference 202. Minor editorial revision of reference list (reference numbers have changed), URLs updated.
2001-08-31
update
sasaki.misao
General Relativity, Cosmology
Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
870
Misao Sasaki
author
Sasaki
Misao
carroll.sean
My research interests include a variety of topics in theoretical physics, especially including cosmology, field theory, and gravitation, or elementary physics more broadly. This is an especially exciting time for this kind of science; a flood of data and suprising observational results are revolutionizing cosmology, new experiments (from accelerators and elsewhere) are invigorating particle physics, and advances in string theory have brought it into closer contact with low-energy physics and gravitation.
Department of Physics, California Institute of Technology, MC 452-48, 1200 East California Boulevard, Pasadena, CA 91125, U.S.A.
850
Sean M. Carroll
author
Carroll
Sean M.
reid.stuart
My research is aimed at developing precision optics formed from novel materials, employing techniques such as surface characterisation, polishing and chemical etching, in addition to thermal treatment, with the goal of developing instrumentation for future gravitational wave observatories.
Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.
Stuart Reid
author
Reid
Stuart
2007-09-07
lrr-2007-4
The Hubble Constant
2007LRR....10....4J
I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. In the last 20 years, much progress has been made and estimates now range between 60 and 75 km s^-1 Mpc^-1, with most now between 70 and 75 km s^-1 Mpc^-1, a huge improvement over the factor-of-2 uncertainty which used to prevail. Further improvements which gave a generally agreed margin of error of a few percent rather than the current 10% would be vital input to much other interesting cosmology. There are several programmes which are likely to lead us to this point in the next 10 years.
4
2007-09-11
2007-09-24
10
publication
pound.adam
Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1
Adam Pound
author
Pound
Adam
lrr-2015-2
I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H_0 values of around 72–74 km s^–1 Mpc^–1, with typical errors of 2–3 km s^–1 Mpc^–1. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67–68 km s^–1 Mpc^–1 and typical errors of 1–2 km s^–1 Mpc^–1. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.
The Hubble Constant
2015LRR....18....2J
2
2014-08-14
2014-03-03
2015-09-24
Major revision, updated and expanded. The number of references has increased from 179 to 242.
18
Cosmology
Hubble constant
publication
2005-11-03
lrr-2005-10
I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. A prime application of characteristic evolution is to compute waveforms via Cauchy-characteristic matching, which is also reviewed.
Characteristic Evolution and Matching
2005LRR.....8...10W
10
2005-10-19
2005-12-08
Updated and extended review, especially Sections 3 and 5.
Number of references increased from 157 to 229.
8
publication
lrr-2004-6
The Motion of Point Particles in Curved Spacetime
2004LRR.....7....6P
This review is concerned with the motion of a point scalar charge, a point electric charge, and a point mass in a specified background spacetime. In each of the three cases the particle produces a field that behaves as outgoing radiation in the wave zone, and therefore removes energy from the particle. In the near zone the field acts on the particle and gives rise to a self-force that prevents the particle from moving on a geodesic of the background spacetime. The self-force contains both conservative and dissipative terms, and the latter are responsible for the radiation reaction. The work done by the self-force matches the energy radiated away by the particle.
The field's action on the particle is difficult to calculate because of its singular nature: The field diverges at the position of the particle. But it is possible to isolate the field's singular part and show that it exerts no force on the particle -- its only effect is to contribute to the particle's inertia. What remains after subtraction is a smooth field that is fully responsible for the self-force. Because this field satisfies a homogeneous wave equation, it can be thought of as a free (radiative) field that interacts with the particle; it is this interaction that gives rise to the self-force.
The mathematical tools required to derive the equations of motion of a point scalar charge, a point electric charge, and a point mass in a specified background spacetime are developed here from scratch. The review begins with a discussion of the basic theory of bitensors (Section 2). It then applies the theory to the construction of convenient coordinate systems to chart a neighbourhood of the particle's word line (Section 3). It continues with a thorough discussion of Green's functions in curved spacetime (Section 4). The review concludes with a detailed derivation of each of the three equations of motion (Section 5).
6
2004-03-26
2004-05-27
7
Electromagnetic field
Curved spacetime
Scalar field
Gravitation
Radiation reaction
Point particles
Self force
Equations of motion
publication
lrr-2005-7-u1
Correction of a few typos in Table 1.
2005-11-28
2005-11-29
update
chamel.nicolas
Institut d’Astronomie et d’Astrophysique, Université Libre de Bruxelles, CP226, Boulevard du Triomphe B-1050 Brussels, Belgium
Nicolas Chamel
author
Chamel
Nicolas
villasenor.eduardo
Quantum Gravity, General Relativity, Mathematical Physics
Instituto Gregorio Millán, Grupo de Modelización y Simulación Numérica, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Spain
Eduardo J. S. Villaseñor
author
Villaseñor
Eduardo J. S.
lrr-2005-6
This article is a guide to theorems on existence and global dynamics of solutions of the Einstein equations. It draws attention to open questions in the field. The local-in-time Cauchy problem, which is relatively well understood, is surveyed. Global results for solutions with various types of symmetry are discussed. A selection of results from Newtonian theory and special relativity that offer useful comparisons is presented. Treatments of global results in the case of small data and results on constructing spacetimes with prescribed singularity structure or late-time asymptotics are given. A conjectural picture of the asymptotic behaviour of general cosmological solutions of the Einstein equations is built up. Some miscellaneous topics connected with the main theme are collected in a separate section.
Theorems on Existence and Global Dynamics for the Einstein Equations
2005-08-02
2005LRR.....8....6R
6
2005-09-28
2005-10-18
1. All sections have been updated and new references added with the result that the total number of references has increased by 40 per cent in comparison with the previous version
2. Section 3.4 (weak null singularities and Price's law) is new
3. Section 3.6 (spatially compact solutions) includes a new discussion of Gowdy spacetimes
4. Section 6.3 (asymptotics for a phase of accelerated expansion) is new
5. The old section 7.3 has been much expanded to constitute the new sections 7.3-7.6.
6. Section 8.4 (cosmic censorship in Gowdy spacetimes) is new.
7. Section 9.6 (the geodesic hypothesis) is new
8
publication
lrr-2008-6
Black Holes in Higher Dimensions
2008-07-04
2008LRR....11....6E
We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.
6
2008-07-07
2008-09-08
11
black holes, string theory, supergravity
publication
postnov.konstantin
Relativistic astrophysics, Binary star evolution, Gravitational waves
Moscow M.V. Lomonosov State University, Sternberg Astronomical Institute, 13 Universitetskij Pr., 119992 Moscow, Russia
Konstantin A. Postnov
author
Postnov
Konstantin A.
spindel.philippe
Ph. Spindel is interested in theoretical physics, mainly gravitation, cosmology, black hole physics, but also in quantum theories and geometry applied to physics.
Service de Mécanique et Gravitation, Université de Mons-Hainaut, Académie Wallonie-Bruxelles, Avenue du Champ de Mars 6, B-7000 Mons, Belgium
Philippe Spindel
author
Spindel
Philippe
lrr-2009-4
The present status of the quasi-local mass, energy-momentum and angular-momentum constructions in general relativity is reviewed. First, the general ideas, concepts, and strategies, as well as the necessary tools to construct and analyze the quasi-local quantities, are recalled. Then, the various specific constructions and their properties (both successes and deficiencies are discussed. Finally, some of the (actual and potential) applications of the quasi-local concepts and specific constructions are briefly mentioned.
Quasi-Local Energy-Momentum and Angular Momentum in General Relativity
2009LRR....12....4S
4
2009-03-24
2008-12-10
2009-06-19
Recent developments of the field as well as some old classical results are included. Almost 120 new references are added, the text is improved and corrected at several points, and the bibliography is updated.
12
General relativity
Quasi-local angular momentum
Witten equations
Quasi-local energy-momentum
Quasi-local mass
publication
2005-06-14
lrr-2005-4
Time-Delay Interferometry
2005LRR.....8....4D
Equal-arm interferometric detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers), the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called Time-Delay Interferometry (TDI). This article provides an overview of the theory and mathematical foundations of TDI as it will be implemented by the forthcoming space-based interferometers such as the Laser Interferometer Space Antenna (LISA) mission. We have purposely left out from this first version of our "Living Review" article on TDI all the results of more practical and experimental nature, as well as all the aspects of TDI that the data analysts will need to account for when analyzing the LISA TDI data combinations. Our forthcoming "second edition" of this review paper will include these topics.
4
2005-05-16
2005-07-15
8
publication
martin-garcia.jose
Gravitational collapse, linear and nonlinear perturbation theory in General Relativity, numerical relativity, tensor computer algebra
Wolfram Research, Inc., 100 Trade Center Drive, Champaign, Illinois 61820, USA
José M. Martín-García
author
Martín-García
José M.
2006-11-10
lrr-2006-6
The Evolution of Compact Binary Star Systems
2006LRR.....9....6P
We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.
6
2006-11-13
2006-12-19
9
astrophysics, binary systems, gravitational wave sources, supernovae, neutron stars, black holes, white dwarfs, AM CVn stars
publication
lrr-2013-7-baker.john
authorOrder
4
lrr-2008-2
History of Astroparticle Physics and its Components
2008-03-14
2008LRR....11....2C
This article gives an outline of the historical events that led to the formation of contemporary astroparticle physics. As a starting point for analyzing the history of astroparticle physics this article will review the various, yet scattered pieces of historical work that have been done so far. To make the picture more complete it will then give a brief survey of the most important fields that have played a role in the development of astroparticle physics as we know it today. It will conclude with an overview of the historical questions that are still open and the rich philosophical implications that lie behind those questions.
2
2008-03-20
2008-05-07
11
astroparticle physics, history of physics, philosophy of physics
publication
stergioulas.nikolaos
Rotating Relativistic Stars, Computational Relativistic Astrophysics
Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124
Greece
797
Nikolaos Stergioulas
author
Stergioulas
Nikolaos
lrr-2012-2
I review the development of numerical evolution codes for general relativity based upon the characteristic initial-value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D-axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black-hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black-hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.
Characteristic Evolution and Matching
2012LRR....15....2W
2
2012-01-04
2011-08-08
2012-01-25
Besides various small changes, Sections 2.1, 3.1.1, 4.2.1 and 6.2 to 6.6 are new, with 54 new references.
15
Characteristic initial value problem
Numerical methods
Numerical relativity
publication
virgo-collaboration
Virgo Collaboration
author
RelAstro
subjectField
8
Relativity in Astrophysics
lrr-2013-8
Classification of Near-Horizon Geometries of Extremal Black Holes
2013-06-17
2013LRR....16....8K
Any spacetime containing a degenerate Killing horizon, such as an extremal black hole, possesses a well-defined notion of a near-horizon geometry. We review such near-horizon geometry solutions in a variety of dimensions and theories in a unified manner. We discuss various general results including horizon topology and near-horizon symmetry enhancement. We also discuss the status of the classification of near-horizon geometries in theories ranging from vacuum gravity to Einstein–Maxwell theory and supergravity theories. Finally, we discuss applications to the classification of extremal black holes and various related topics. Several new results are presented and open problems are highlighted throughout.
8
2013-09-11
2013-09-25
16
Extremal black holes
Near-horizon geometry
Black holes
publication
lrr-2014-2
To be observed and analyzed by the network of gravitational wave detectors on ground (LIGO, VIRGO, etc.) and by the future detectors in space (eLISA, etc.), inspiralling compact binaries -- binary star systems composed of neutron stars and/or black holes in their late stage of evolution -- require high-accuracy templates predicted by general relativity theory. The gravitational waves emitted by these very relativistic systems can be accurately modelled using a high-order post-Newtonian gravitational wave generation formalism. In this article, we present the current state of the art on post-Newtonian methods as applied to the dynamics and gravitational radiation of general matter sources (including the radiation reaction back onto the source) and inspiralling compact binaries. We describe the post-Newtonian equations of motion of compact binaries and the associated Lagrangian and Hamiltonian formalisms, paying attention to the self-field regularizations at work in the calculations. Several notions of innermost circular orbits are discussed. We estimate the accuracy of the post-Newtonian approximation and make a comparison with numerical computations of the gravitational self-force for compact binaries in the small mass ratio limit. The gravitational waveform and energy flux are obtained to high post-Newtonian order and the binary's orbital phase evolution is deduced from an energy balance argument. Some landmark results are given in the case of eccentric compact binaries -- moving on quasi-elliptical orbits with non-negligible eccentricity. The spins of the two black holes play an important role in the definition of the gravitational wave templates. We investigate their imprint on the equations of motion and gravitational wave phasing up to high post-Newtonian order (restricting to spin-orbit effects which are linear in spins), and analyze the post-Newtonian spin precession equations as well as the induced precession of the orbital plane.
Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries
2014LRR....17....2B
2
2014-01-27
2013-10-06
2014-02-13
Major revision, updated and expanded. About 180 new references.
17
Gravitational radiation
Post-Newtonian approximations
Multipolar expansion
Inspiralling compact binary
publication
ligo-scientific-collaboration
LIGO Scientific Collaboration
author
lrr-2003-5
Testing General Relativity with Pulsar Timing
2003LRR.....6....5S
Pulsars of very different types, including isolated objects and binaries (with short- and long-period orbits, and white-dwarf and neutron-star companions) provide the means to test both the predictions of general relativity and the viability of alternate theories of gravity. This article presents an overview of pulsars, then discusses the current status of and future prospects for tests of equivalence-principle violations and strong-field gravitational experiments.
5
2003-06-03
2003-09-09
6
neutron stars
theories of gravity
astronomical observations
white dwarfs
gravitational radiation
pulsars
tests of relativistic gravity
binary systems
publication
verdaguer.enric
Soliton solutions of Einstein's equations; Quantum effects in the early universe: cosmic strings and inflation; Quantum field theory in curved spacetime; Semiclassical and stochastic gravity; Quantum to classical transitions and open quantum systems; Vaccum decay in field theory
Departament de Física Fonamental and C.E.R. in Astrophysics, Particles and Cosmology
Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona, Spain
412
Enric Verdaguer
author
Verdaguer
Enric
lrr-2012-1-kozameh.carlos
authorOrder
3
MathRel
subjectField
4
Mathematical Relativity
vallisneri.michele
Gravitational-wave science
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
Michele Vallisneri
author
Vallisneri
Michele
lasenby.anthony
Anisotropy of the microwave background, cosmology, the Galactic Centre, telescope surface profile measurement, phase reconstruction problems, atmospheric spectral line broadening. Geometric algebras, the application of Clifford Algebras in physics.
Mullard Radio Astronomy Observatory, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE, U.K.
791
Anthony N. Lasenby
author
Lasenby
Anthony N.
lrr-2014-6-tinto.massimo
authorOrder
1
ExpFound
subjectField
1
Experimental Foundations of Gravitation
new.kimberly
Los Alamos National Laboratory, MS T087, X-4 Los Alamos, New Mexico 87545, U.S.A.
934
Kimberly C.B. New
author
New
Kimberly C.B.
lrr-2000-2
Numerical Hydrodynamics in General Relativity
The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A representative sample of available numerical schemes is discussed and particular emphasis is paid to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of relevant astrophysical simulations in strong gravitational fields, including gravitational collapse, accretion onto black holes and evolution of neutron stars, is also presented.
2
2000-03-28
2000-05-08
3
publication
yunes.nicolas
To use general relativity and gravitation to connect observational astrophysics, high-energy particle
physics, string theory and quantum gravity. Primary interests include gravitational wave detection and mod-
eling, dynamics of compact objects, and tests of alternative theories of gravity.
Department of Physics, Montana State University, Bozeman, MO 59717, USA
Nicolás Yunes
author
Yunes
Nicolás
toth.viktor
I am a software developer and author of computer books. I also work on some problems in theoretical physics.
Ottawa, ON K1N 9H5, Canada
Viktor T. Toth
author
Toth
Viktor T.
2005-11-21
lrr-2006-2
The galactic population of globular clusters are old, dense star systems, with a typical cluster containing 10^4 - 10^7 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker-Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
Relativistic Binaries in Globular Clusters
2006LRR.....9....2B
2
2006-01-09
2006-02-07
Minor revisions to Sections 1, 2, and 4.
Substantial additions to Sections 3 (to incorporate new observations) and 5 (to include new population synthesis models).
Added roughly 60 new references.
9
accretion, accretion disks, astronomical observations, astronomy, astrophysics, binary systems, black holes, dynamical systems, gravitational wave sources, neutron stars, pulsars, radio astronomy, stars, white dwarfs
publication
lrr-2012-11
The Kerr/CFT Correspondence and its Extensions
2012-04-23
2012LRR....15...11C
We present a first-principles derivation of the main results of the Kerr/CFT correspondence and its extensions using only tools from gravity and quantum field theory, filling a few gaps in the literature when necessary. Firstly, we review properties of extremal black holes that imply, according to semi-classical quantization rules, that their near-horizon quantum states form a centrally-extended representation of the one-dimensional conformal group. This motivates the conjecture that the extremal Kerr and Reissner–Nordström black holes are dual to the chiral limit of a two-dimensional CFT. We also motivate the existence of an SL (2,ℤ) family of two-dimensional CFTs, which describe in their chiral limit the extremal Kerr–Newman black hole. We present generalizations in anti-de Sitter spacetime and discuss other matter-coupling and higher-derivative corrections. Secondly, we show how a near-chiral limit of these CFTs reproduces the dynamics of near-superradiant probes around near-extremal black holes in the semi-classical limit. Thirdly, we review how the hidden conformal symmetries of asymptotically-flat black holes away from extremality, combined with their properties at extremality, allow for a microscopic accounting of the entropy of non-extremal asymptotically-flat rotating or charged black holes. We conclude with a list of open problems.
11
2012-06-13
2012-10-22
15
conformal field theory
Black holes
holography
AdS/CFT
publication
lrr-2012-4
The article reviews the statistical theory of signal detection in application to analysis of deterministic gravitational-wave signals in the noise of a detector. Statistical foundations for the theory of signal detection and parameter estimation are presented. Several tools needed for both theoretical evaluation of the optimal data analysis methods and for their practical implementation are introduced. They include optimal signal-to-noise ratio, Fisher matrix, false alarm and detection probabilities, ℱ-statistic, template placement, and fitting factor. These tools apply to the case of signals buried in a stationary and Gaussian noise. Algorithms to efficiently implement the optimal data analysis techniques are discussed. Formulas are given for a general gravitational-wave signal that includes as special cases most of the deterministic signals of interest.
Gravitational-Wave Data Analysis. Formalism and Sample Applications: The Gaussian Case
2012LRR....15....4J
4
2012-02-14
2011-07-16
2012-03-09
Material of the previous version of the review was partially reorganized and updated, 46 new references were added. 1. Section 2 was rewritten and extended, several new references were added. 2. Some parts of the former Section 4 were moved to the present Section 3, which is now a brief general introduction to the statistical theory of signal detection and of estimation of signals parameters. Some new references were added. 3. The present Section 4 is a partially rewritten (using some new, more convenient notation) and extended version of the former Sections 4.3 – 4.9. The gravitational-wave signal considered here was generalized from a 4-amplitude-parameter case to an n-amplitude-parameter case, where n is arbitrary. New Section 4.1.1 about targeted searches was added, and new Section 4.4.1 on the covering problem was created with references to constructions of various grids of templates for searches of continuous gravitational waves. 4. The present Section 5 is an expanded version of the former Section 4.10 with addition of several recent references. 5. The present Section 6 is an expanded version of the former Section 4.11 with new discussion of optimal filtering for non-stationary data and description of a test (Grubbs’ test) to detect outliers in data.
15
parameter estimation
gravitational waves
signal detection
publication
lrr-2013-9
Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays
2013-04-11
2013LRR....16....9Y
This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein's theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime. Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.
9
2013-10-08
2013-11-06
16
Observational tests
Gravitational waves
Pulsar timing
Alternative theories
Experimental tests
General relativity
Compact binaries
publication
GravWave
subjectField
2
Gravitational Waves
persson.daniel
My research so far has been related in various ways to the investigation of the underlying algebraic structures in supergravity and string theory. One point of entry into this topic is the analysis of gravitational theories close to a spacelike singularity (the "BKL-limit"), for which infinite-dimensional Kac-Moody algebras turn out to play an important role. More precisely, for many theories of interest, the dynamics in the vicinity of a spacelike singularity is controlled by hyperbolic Coxeter groups, corresponding to Weyl groups of hyperbolic Kac-Moody algebras. The BKL-limit therefore reveals a "hidden" arithmetic structure in theories coupled to gravity. Recently, I have investigated how this structure is modified when the spatial dimensions are described by compact manifolds of nontrivial topology. From another point of view, it is well known that similar arithmetic structures arise in string/M-theory in the form of discrete U-duality groups. Motivated by this, I am also studying the construction of arithmetic subgroups of Lie groups, and their relation with automorphic forms.
Institut für Theoretische Physik, ETH Zürich, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
Daniel Persson
author
Persson
Daniel
2009-04-28
lrr-2009-6
Null Geodesic Congruences, Asymptotically-Flat Spacetimes and Their Physical Interpretation
2009LRR....12....6A
A priori, there is nothing very special about shear-free or asymptotically shear-free null geodesic congruences. Surprisingly, however, they turn out to possess a large number of fascinating geometric properties and to be closely related, in the context of general relativity, to a variety of physically significant effects. It is the purpose of this paper to try to fully develop these issues.
This work starts with a detailed exposition of the theory of shear-free and asymptotically shear-free null geodesic congruences, i.e., congruences with shear that vanishes at future conformal null infinity. A major portion of the exposition lies in the analysis of the space of regular shear-free and asymptotically shear-free null geodesic congruences. This analysis leads to the space of complex analytic curves in complex Minkowski space. They in turn play a dominant role in the applications.
The applications center around the problem of extracting interior physical properties of an asymptotically-flat spacetime directly from the asymptotic gravitational (and Maxwell) field itself, in analogy with the determination of total charge by an integral over the Maxwell field at infinity or the identification of the interior mass (and its loss) by (Bondi’s) integrals of the Weyl tensor, also at infinity.
More specifically, we will see that the asymptotically shear-free congruences lead us to an asymptotic definition of the center-of-mass and its equations of motion. This includes a kinematic meaning, in terms of the center-of-mass motion, for the Bondi three-momentum. In addition, we obtain insights into intrinsic spin and, in general, angular momentum, including an angular-momentum–conservation law with well-defined flux terms. When a Maxwell field is present, the asymptotically shear-free congruences allow us to determine/define at infinity a center-of-charge world line and intrinsic magnetic dipole moment.
6
2009-08-05
2009-09-11
12
Spin-coefficient formalism
Asymptotic flatness
H-space
Shear-free congruences
publication
lrr-2001-1
The Cosmological Constant
2001LRR.....4....1C
This is a review of the physics and cosmology of the cosmological constant. Focusing on recent developments, I present a pedagogical overview of cosmology in the presence of a cosmological constant, observational constraints on its magnitude, and the physics of a small (and potentially nonzero) vacuum energy.
1
2001-01-29
2001-02-07
4
cosmological constant
vacuum energy
cosmology
publication
lrr-2013-9-yunes.nicolas
authorOrder
1
lrr-2013-7-vallisneri.michele
authorOrder
2
lrr-2004-8
Measuring our Universe from Galaxy Redshift Surveys
2004LRR.....7....8L
Galaxy redshift surveys have achieved significant progress over the last couple of decades. Those surveys tell us in the most straightforward way what our local Universe looks like. While the galaxy distribution traces the bright side of the Universe, detailed quantitative analyses of the data have even revealed the dark side of the Universe dominated by non-baryonic dark matter as well as more mysterious dark energy (or Einstein's cosmological constant). We describe several methodologies of using galaxy redshift surveys as cosmological probes, and then summarize the recent results from the existing surveys. Finally we present our views on the future of redshift surveys in the era of precision cosmology.
8
2004-06-18
2004-07-16
7
statistical methods
dark matter
large-scale structure of universe
cosmology
publication
2005-10-10
lrr-2005-11
Loop Quantum Cosmology
2005LRR.....8...11B
Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical space-time inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding space-time is then modified. One particular realization is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. Main effects are introduced into effective classical equations which allow to avoid interpretational problems of quantum theory. They give rise to new kinds of early universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function which allows to extend space-time beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of space-time arising in loop quantum gravity and its application to cosmology sheds new light on more general issues such as time.
11
2005-10-28
2005-12-08
8
publication
palenzuela.carlos
Numerical Relativity, Gravitational Radiation from compact bodies (boson and neutron stars, black holes), Blandford-Znajeck mechanism, approaches beyond ideal MHD
Canadian Institute for Theoretical Astrophysics, Toronto, Ontario M5S 3H8, Canada
Carlos Palenzuela
author
Palenzuela
Carlos
henneaux.marc
Black Holes, Singularities and Belinskii-Khalatnikov-Lifshitz analysis, Quantum Gravity, M-Theory, Dualities
Physique Théorique et Mathématique, Université Libre de Bruxelles & International Solvay Institutes, Boulevard du Triomphe, ULB – C.P. 231, B-1050 Bruxelles, Belgium
Marc Henneaux
author
Henneaux
Marc
lrr-2002-3
Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries
2002LRR.....5....3B
The article reviews the current status of a theoretical approach to the problem of the emission of gravitational waves by isolated systems in the context of general relativity. Part aaa of the article deals with general post-Newtonian sources. The exterior field of the source is investigated by means of a combination of analytic post-Minkowskian and multipolar approximations. The physical observables in the far-zone of the source are described by a specific set of radiative multipole moments. By matching the exterior solution to the metric of the post-Newtonian source in the near-zone we obtain the explicit expressions of the source multipole moments. The relationships between the radiative and source moments involve many non-linear multipole interactions, among them those associated with the tails (and tails-of-tails) of gravitational waves. Part bbb of the article is devoted to the application to compact binary systems. We present the equations of binary motion, and the associated Lagrangian and Hamiltonian, at the third post-Newtonian (3PN) order beyond the Newtonian acceleration. The gravitational-wave energy flux, taking consistently into account the relativistic corrections in the binary moments as well as the various tail effects, is derived through 3.5PN order with respect to the quadrupole formalism. The binary's orbital phase, whose prior knowledge is crucial for searching and analyzing the signals from inspiralling compact binaries, is deduced from an energy balance argument.
3
2002-02-01
2002-04-30
5
inspiralling compact binary
multipolar expansion
post-Newtonian approximation
gravitational radiation
publication
rezzolla.luciano
I am a relativistic astrophysicist, i.e., a physicist who uses Einstein’s theory of general relativity to describe and explain high-energy astronomical observations of black holes and neutron stars. To do this I combine analytical perturbative tools with numerical nonlinear simulations in which I solve the Einstein equations together with those of relativistic hydrodynamics or magnetohydrodynamics.
Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
Luciano Rezzolla
author
Rezzolla
Luciano
rangamani
University of California, Davis, USA
Mukund Rangamani
ebMember
rangamani
Rangamani
Mukund
lrr-2014-2-u2
Minor update. Added 12 new references. Added a discussion on 4PN equations of motion.
2016-02-16
2016-02-16
update
font.jose
Main field: Relativistic Astrophysics. Specific field: Numerical Relativistic Hydrodynamics.
Departamento de Astronomía y Astrofísica, Edificio de Investigación "Jeroni Muñoz", Universidad de Valencia, Dr. Moliner 50, E-46100 Burjassot (Valencia), Spain
822
José A. Font
author
Font
José A.
lrr-1999-1
Speeds of Propagation in Classical and Relativistic Extended Thermodynamics
1999LRR.....2....1M
The Navier-Stokes-Fourier theory of viscous, heat-conducting fluids provides parabolic equations and thus predicts infinite pulse speeds. Naturally this feature has disqualified the theory for relativistic thermodynamics which must insist on finite speeds and, moreover, on speeds smaller than $c$. The attempts at a remedy have proved heuristically important for a new systematic type of thermodynamics: Extended thermodynamics. That new theory has symmetric hyperbolic field equations and thus it provides finite pulse speeds. Extended thermodynamics is a whole hierarchy of theories with an increasing number of fields when gradients and rates of thermodynamic processes become steeper and faster. The first stage in this hierarchy is the 14-field theory which may already be a useful tool for the relativist in many applications. The 14 fields -- and further fields -- are conveniently chosen from the moments of the kinetic theory of gases. The hierarchy is complete only when the number of fields tends to infinity. In that case the pulse speed of non-relativistic extended thermodynamics tends to infinity while the pulse speed of relativistic extended thermodynamics tends to $c$, the speed of light. In extended thermodynamics symmetric hyperbolicity -- and finite speeds -- are implied by the concavity of the entropy density. This is still true in relativistic thermodynamics for a privileged entropy density which is the entropy density of the rest frame for non-degenerate gases.
1
1999-03-01
1999-06-14
2
Thermodynamics
publication
lrr-2000-5
Initial Data for Numerical Relativity
2000LRR.....3....5C
Initial data are the starting point for any numerical simulation. In the case of numerical relativity, Einstein's equations constrain our choices of these initial data. We will examine several of the formalisms used for specifying Cauchy initial data in the 3+1 decomposition of Einstein's equations. We will then explore how these formalisms have been used in constructing initial data for spacetimes containing black holes and neutron stars. In the topics discussed, emphasis is placed on those issues that are important for obtaining astrophysically realistic initial data for compact binary coalescence.
5
2000-10-26
2000-11-14
3
Black holes
Constraint equations
Neutron stars
Binary systems
Initial value problem
Numerical relativity
ADM formalism
publication
lrr-2004-5
Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory
2004LRR.....7....5B
This article is meant as a summary and introduction to the ideas of effective field theory as applied to gravitational systems, ideas which provide the theoretical foundations for the modern use of general relativity as a theory from which precise predictions are possible.
5
2004-03-16
2004-04-08
7
effective field theories
quantum gravity
general theory of relativity
publication
weyher
Manager Research & Development (1997-2011)
Christina Weyher
teamMember
d
Weyher
Christina
szabados.laszlo
Wigner Research Centre for Physics of the Hungarian Academy of Sciences, H-1525 Budapest 114, P.O. Box 49, Hungary
648
László B. Szabados
author
Szabados
László B.
cirkel.vanessa
Cosmic ray studies in the early 20th century and its relation to modern (astroparticle-) physics. Problems of philosophy of science, using particle physics as an example.
Technische Universität Dortmund, Department of Human Sciences and Theology (14), Emil-Figge-Str. 50, 44221 Dortmund, Germany and Interdisciplinary Center for Science and Technology Studies: Normative and Historical Perspectives (IZWT), Bergische Universität Wuppertal, Gaußstraße 20, 42119 Wuppertal
Vanessa Cirkel-Bartelt
author
Cirkel-Bartelt
Vanessa
tagoshi.hideyuki
Department of Earth and Space Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
894
Hideyuki Tagoshi
author
Tagoshi
Hideyuki
2005-11-04
lrr-2005-12
Analogue Gravity
2005LRR.....8...12B
Analogue models of (and for) gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing) and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity).
12
2005-11-07
2005-12-16
8
analog models, gravity
publication
vinet.jean-yves
Observatoire de la Côte d’Azur (ARTEMIS), Université de Nice-Sophia Antipolis, 06304 Nice, France
Jean-Yves Vinet
author
Vinet
Jean-Yves
lrr-2011-6
Coalescence of Black Hole-Neutron Star Binaries
2010-12-20
2011LRR....14....6S
We review the current status of general relativistic studies for the coalescence of black hole-neutron star (BH-NS) binaries. First, procedures for a solution of BH-NS binaries in quasi-equilibrium circular orbits and the numerical results, such as quasi-equilibrium sequence and mass-shedding limit, of the high-precision computation, are summarized. Then, the current status of numerical-relativity simulations for the merger of BH-NS binaries is described. We summarize our understanding for the merger and/or tidal disruption processes, the criterion for tidal disruption, the properties of the remnant formed after the tidal disruption, gravitational waveform, and gravitational-wave spectrum.
6
2011-07-07
2011-08-29
14
gravitational waves
numerical relativity
black hole
neutron star
publication
novak.jerome
Compact stars, gravitational waves, numerical relativity, supernovae.
Laboratoire Univers et Théories, UMR 8102 du C.N.R.S., Observatoire de Paris, F-92195 Meudon Cedex, France
Jérôme Novak
author
Novak
Jérôme
lrr-2012-10
Modified Newtonian Dynamics (MOND): Observational Phenomenology and Relativistic Extensions
2011-12-16
2012LRR....15...10F
A wealth of astronomical data indicate the presence of mass discrepancies in the Universe. The motions observed in a variety of classes of extragalactic systems exceed what can be explained by the mass visible in stars and gas. Either (i) there is a vast amount of unseen mass in some novel form - dark matter - or (ii) the data indicate a breakdown of our understanding of dynamics on the relevant scales, or (iii) both. Here, we first review a few outstanding challenges for the dark matter interpretation of mass discrepancies in galaxies, purely based on observations and independently of any alternative theoretical framework. We then show that many of these puzzling observations are predicted by one single relation - Milgrom's law - involving an acceleration constant a_0 (or a characteristic surface density Σ_† = a_0∕G) on the order of the square-root of the cosmological constant in natural units. This relation can at present most easily be interpreted as the effect of a single universal force law resulting from a modification of Newtonian dynamics (MOND) on galactic scales. We exhaustively review the current observational successes and problems of this alternative paradigm at all astrophysical scales, and summarize the various theoretical attempts (TeVeS, GEA, BIMOND, and others) made to effectively embed this modification of Newtonian dynamics within a relativistic theory of gravity.
10
2012-04-30
2012-09-07
15
equations of motion
fundamental physics
astronomical observations
cosmology
extragalactic astronomy
Newtonian limit
theories of gravity
astrophysics
publication
lrr-2013-3
The Spin-Foam Approach to Quantum Gravity
2011-09-13
2013LRR....16....3P
This article reviews the present status of the spin-foam approach to the quantization of gravity. Special attention is payed to the pedagogical presentation of the recently-introduced new models for four-dimensional quantum gravity. The models are motivated by a suitable implementation of the path integral quantization of the Plebanski formulation of gravity on a simplicial regularization. The article also includes a self contained treatment of 2+1 gravity. The simple nature of the latter provides the basis and a perspective for the analysis of both conceptual and technical issues that remain open in four dimensions.
3
2012-06-11
2013-02-14
16
Quantum gravity
publication
carlip.steven
quantum gravity; theoretical particle physics; mathematical physics
Department of Physics, University of California, Davis, CA 95616, U.S.A.
864
Steven Carlip
author
Carlip
Steven
blanchet.luc
Research interests are mostly theoretical, on Einstein's general relativity and gravitational theories, including the problem of motion of bodies in general relativity, the implementation of high-order approximation methods in that theory, the problem of the generation of gravitational radiation by astrophysical sources, and the one of the analysis of gravitational waves when they are observed by current experiments. Has more recently been interested in the problem of dark matter in cosmology.
Institut d'Astrophysique de Paris, 98bis boulevard Arago, 75014 Paris, France
29
Luc Blanchet
author
Blanchet
Luc
freise.andreas
My main research interests are laser interferometry and optical techniques for gravitational wave detectors.
School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK
Andreas Freise
author
Freise
Andreas
lrr-2012-3
Brane Effective Actions, Kappa-Symmetry and Applications
2011-10-24
2012LRR....15....3S
This is a review on brane effective actions, their symmetries and some of their applications. Its first part covers the Green–Schwarz formulation of single M- and D-brane effective actions focusing on kinematical aspects: the identification of their degrees of freedom, the importance of world volume diffeomorphisms and kappa symmetry to achieve manifest spacetime covariance and supersymmetry, and the explicit construction of such actions in arbitrary on-shell supergravity backgrounds.
Its second part deals with applications. First, the use of kappa symmetry to determine supersymmetric world volume solitons. This includes their explicit construction in flat and curved backgrounds, their interpretation as Bogomol’nyi–Prasad–Sommerfield (BPS) states carrying (topological) charges in the supersymmetry algebra and the connection between supersymmetry and Hamiltonian BPS bounds. When available, I emphasise the use of these solitons as constituents in microscopic models of black holes. Second, the use of probe approximations to infer about the non-trivial dynamics of strongly-coupled gauge theories using the anti de Sitter/conformal field theory (AdS/CFT) correspondence. This includes expectation values of Wilson loop operators, spectrum information and the general use of D-brane probes to approximate the dynamics of systems with small number of degrees of freedom interacting with larger systems allowing a dual gravitational description.
Its final part briefly discusses effective actions for N D-branes and M2-branes. This includes both Super-Yang-Mills theories, their higher-order corrections and partial results in covariantising these couplings to curved backgrounds, and the more recent supersymmetric Chern–Simons matter theories describing M2-branes using field theory, brane constructions and 3-algebra considerations.
3
2012-01-09
2012-02-27
15
Solitons
AdS/CFT
Supersymmetry
Non-abelian gauge theories
Kappa-symmetry
publication
burgess.cliff
At present my interests lie at the interface between string theory and lower-energy physics, with a particular emphasis on how the discovery of D-branes may have observable consequences in experiments and in cosmology. To the extent that there is a theme to my research, it would be the use of effective field theory techniques throughout high-energy physics and other fields.
Department of Physics and Astronomy, ABB-324, McMaster University, 1280 Main St. W, Hamilton, ON, L8S 4M1, Canada
984
Cliff P. Burgess
author
Burgess
Cliff P.
lrr-2006-3
The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed. Einstein’s equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and other binary pulsar systems have yielded other tests, especially of strong-field effects. When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.
The Confrontation between General Relativity and Experiment
2006LRR.....9....3W
3
2006-02-27
2006-02-20
2006-03-27
Updated article and references (added 143).
9
tests of relativistic gravity, theories of gravity, post-Newtonian limit, gravitational radiation
publication
adamo.timothy
Classical general relativity, asymptotic gravitation, null geodesic congruences and good cut formalism, twistor theory, complex geometry and gravitation
University of Oxford, Mathematical Institute, 24-29 St Giles, Oxford, OX1 3LB, U.K.
Timothy M. Adamo
author
Adamo
Timothy M.
lrr-1998-5
Characteristic Evolution and Matching
We review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress is traced from the early stage of 1D feasibility studies to current 3D black hole codes that run forever. A prime applicationof characteristic evolution is Cauchy-characteristic matching, which is also reviewed.
5
1998-03-05
1998-05-08
1
publication
anninos.peter
University of California, Lawrence Livermore National Laboratory
7
Peter Anninos
author
Anninos
Peter
lrr-2002-1
This Living Review updates a previous version which is itself an update of a review article. Numerical exploration of the properties of singularities could, in principle, yield detailed understanding of their nature in physically realistic cases. Examples of numerical investigations into the formation of naked singularities, critical behavior in collapse, passage through the Cauchy horizon, chaos of the Mixmaster singularity, and singularities in spatially inhomogeneous cosmologies are discussed.
Numerical Approaches to Spacetime Singularities
2002LRR.....5....1B
1
2001-12-17
2002-01-14
Approximately 60 new references have been included. All topics in the original review have been updated. The section on inhomogeneous cosmologies has been rewritten to the greatest extent.
5
numerical relativity
singularities
publication
lrr-2004-4
Quasi-Local Energy-Momentum and Angular Momentum in GR: A Review Article
2004LRR.....7....4S
The present status of the quasi-local mass-energy-momentum and angular momentum constructions in general relativity is reviewed. First the general ideas, concepts and strategies as well as the necessary tools to construct and analyze the quasi-local quantities are recalled. Then the various specific constructions and their properties (both successes and defects) are discussed. Finally, some of the (actual and potential) applications of the quasi-local concepts and specific constructions are briefly mentioned.
This review is based on the talks given at the Erwin Schrödinger Institut, Vienna, in July 1997, at the Universität Tübingen, in May 1998 and at the National Center for Theoretical Sciences in Hsinchu and at the National Central University, Chungli, Taiwan, in July 2000.
4
2004-02-27
2004-03-16
7
General relativity, Quasi-local angular momentum, Quasi-local energy-momentum, Quasi-local mass
publication
kozameh.carlos
General Relativity, Quantum Electrodynamics, Classical and Quantum Field Theory, Quantum Gravity
Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Argentina
Carlos Kozameh
author
Kozameh
Carlos
reuter.martin
Institute of Physics, University of Mainz, Staudingerweg 7, 55099 Mainz, Germany
Martin Reuter
author
Reuter
Martin
lrr-2001-4
The Confrontation between General Relativity and Experiment
2001LRR.....4....4W
The status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law will search for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational wave damping has been detected in an amount that agrees with general relativity to half a percent using the Hulse-Taylor binary pulsar, and new binary pulsar systems may yield further improvements.When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.
4
2001-01-25
2001-05-11
4
tests of relativistic gravity
post-Newtonian limit
theories of gravity
gravitational radiation
publication
lrr-2014-6-dhurandhar.sanjeev
authorOrder
2
merkowitz.stephen
Gravitational wave detection, experimental gravitation, and precision measurements of the gravitational constant.
NASA Goddard Space Flight Center, Greenbelt, MD 20771, U.S.A.
Stephen M. Merkowitz
author
Merkowitz
Stephen M.
schutz
Director emeritus, MPI for Gravitational Physics, Germany
Editor in Chief
Bernard F. Schutz
ebMember
schutz
Schutz
Bernard F.
lrr-1999-2
Quasi-Normal Modes of Stars and Black Holes
1999LRR.....2....2K
Perturbations of stars and black holes have been one of the main topics of relativistic astrophysics for the last few decades. They are of particular importance today, because of their relevance to gravitational wave astronomy. In this review we present the theory of quasi-normal modes of compact objects from both the mathematical and astrophysical points of view. The discussion includes perturbations of black holes (Schwarzschild, Reissner-Nordström, Kerr and Kerr-Newman) and relativistic stars (non-rotating and slowly-rotating). The properties of the various families of quasi-normal modes are described, and numerical techniques for calculating quasi-normal modes reviewed. The successes, as well as the limits, of perturbation theory are presented, and its role in the emerging era of numerical relativity and supercomputers is discussed.
2
1999-08-31
1999-09-16
2
publication
ringstroem.hans
I do research in mathematical general relativity, in particular in mathematical cosmology.
Department of Mathematics, Royal Institute of Technology, S-100 44 Stockholm, Sweden
Hans Ringström
author
Ringström
Hans
NumRel
subjectField
5
Numerical Relativity
lrr-2000-1
Local and Global Existence Theorems for the Einstein Equations
3
This article is a guide to the literature on existence theorems for the Einstein equations which also draws attention to open problems in the field. The local in time Cauchy problem, which is relatively well understood, is treated first. Next global results for solutions with symmetry are discussed. A selection of results from Newtonian theory and special relativity which offer useful comparisons is presented. This is followed by a survey of global results in the case of small data and results on constructing spacetimes with given singularity structure. The article ends with some miscellaneous topics connected with the main theme.
1
2000-01-04
2000-01-07
Article revision that included substantial additions to various sections, the number of references nearly doubled
publication
lrr-2004-9
Gravitational Lensing from a Spacetime Perspective
2004LRR.....7....9P
The theory of gravitational lensing is reviewed from a spacetime perspective, without quasi-Newtonian approximations. More precisely, the review covers all aspects of gravitational lensing where light propagation is described in terms of lightlike geodesics of a metric of Lorentzian signature. It includes the basic equations and the relevant techniques for calculating the position, the shape, and the brightness of images in an arbitrary general-relativistic spacetime. It also includes general theorems on the classification of caustics, on criteria for multiple imaging, and on the possible number of images. The general results are illustrated with examples of spacetimes where the lensing features can be explicitly calculated, including the Schwarzschild spacetime, the Kerr spacetime, the spacetime of a straight string, plane gravitational waves, and others.
9
2004-07-08
2004-09-17
7
gravitational lenses
differential geometry
publication
tiglio.manuel
Sources of gravitational waves: black holes, neutron stars; High order and spectral methods in complex geometries; High performance computing
Center for Scientific Computation and Mathematical Modeling, Department of Physics, Joint Space Sciences Institute. Maryland Center for Fundamental Physics, University of Maryland, College Park, MD 20742, USA
Manuel Tiglio
author
Tiglio
Manuel
dhurandhar.sanjeev
Prof. Dhurandhar's reseach is on gravitational wave data analysis and computer modelling of gravitational wave detectors. He has worked on efficient search algorithms for ground-based detectors for inspiraling compact binaries. Recently, he used commutative algebraic methods for canceling laser frequency noise in LISA. Prof Dhurandhar has collaborations with major detector groups world-wide and has been a member of the LIGO Science Collaboration since 2000.
IUCAA, Post Bag 4, Ganeshkhind, Pune 411 007, India
Sanjeev V. Dhurandhar
author
Dhurandhar
Sanjeev V.
lrr-2011-5-reid.stuart
authorOrder
2
lrr-2011-3
Analogue gravity is a research programme which investigates analogues of general relativistic gravitational fields within other physical systems, typically but not exclusively condensed matter systems, with the aim of gaining new insights into their corresponding problems. Analogue models of (and for) gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing) and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity).
Analogue Gravity
2011LRR....14....3B
3
2011-02-28
2010-12-14
2011-05-11
Completely revised and updated previous version. Significantly extended Sections 2.4, 3, 4.1, 4.2, 5, and 7. Introduced new Section 6. Eight new figures have been added. The number of references increased from 434 to 702.
14
Gravity
Analogue gravity
Analog models
publication
amendola.luca
Cosmology: theory and observations, Theories of modified gravity, Statistical tools in cosmology
Institut für Theoretische Physik, Philosophenweg 16, D-69120 Heidelberg
Luca Amendola
author
Amendola
Luca
rasio.frederic
Dynamical evolution of dense star clusters, Coalescing compact binaries, Stellar collisions and Blue Stragglers, Extrasolar planetary systems
Center for Interdisciplinary Exploration and Research in Astrophysics, and Department of Physics & Astronomy, Northwestern University, 2145 Sheridan Road, Evanston IL 60208, USA
Frederic A. Rasio
author
Rasio
Frederic A.
lrr-2015-1
Exploring New Physics Frontiers Through Numerical Relativity
2014-04-02
2015LRR....18....1C
The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein’s equations – along with some spectacular results – in various setups.
We review techniques for solving Einstein’s equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology.
1
2014-08-29
2015-09-21
18
Black holes
Numerical methods
Trans-Planckian scattering
Gravitation
Extra dimensions
Extensions of the standard model
Alternative theories of gravity
publication
rowan.sheila
Gravitational Wave Detection on ground (GEO 600 and Advanced LIGO); ultra sensitive mechanical systems, and investigation of materials of ultra-low mechanical loss, lasers for Gravitational Wave Detectors.
Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.
772
Sheila Rowan
author
Rowan
Sheila
cook.greg
My research interest are in numerical realativity and relativistic astrophysics. My research is centered on the simulation of compact binary systems and is currently focused on techniques for constructing astrophysically realistic initial data for binary black hole configurations.
Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109-7507, U.S.A.
74
Gregory B. Cook
author
Cook
Gregory B.
lrr-2010-5
The observable universe could be a 1+3-surface (the “brane”) embedded in a 1+3+d-dimensional spacetime (the “bulk”), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (∼ TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity “leaks” into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall–Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies – the 5-dimensional Dvali–Gabadadze–Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.
Brane-World Gravity
2010LRR....13....5M
5
2010-09-06
2010-04-21
2010-09-14
Inserted subsections on numerical solutions in Sections 6 and 7 and five figures. Added new Subsection 2.2 on the Randall–Sundrum model in string theory. Added new Section 9 on Dvali–Gabadadze–Porrati models and nine figures. Added new Section 10 on 6-dimensional models and one figure. Added about 100 new references.
13
M theory
Brane-world models
publication
lrr-1998-2
Physical and Relativistic Numerical Cosmology
In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark--hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.
2
1998-01-15
1998-01-26
1
publication
QuanGR
subjectField
7
Quantum General Relativity
milosavljevic.milos
Massive black holes; the Galactic center; galaxy formation; galaxy clusters; plasma astrophysics.
The University of Texas, C1400, Department of Astronomy, 2511 Speedway, RLM 15.306, Austin, TX 78712, U.S.A.
Miloš Milosavljević
author
Milosavljević
Miloš
andreasson.hakan
My research is in general relativity and I am interested in questions about spacetime singularities and cosmic censorship. The cosmic censorship conjecture was proposed by Roger Penrose in the sixties and the hypothesis is that spacetime singularities are always hidden within black holes and cannot be seen (i.e. there are no "naked singularities"). In my research I primarily work on global existence for solutions to Einstein's equations and in particular to the Einstein-Vlasov system where the matter is modelled by kinetic theory. A global existence theorem is the first step towards an understanding of cosmic censorship. I am also interested in kinetic equations in general (on a flat background spacetime) such as the Maxwell-Vlasov system, the Vlasov-Poisson system and the relativistic Boltzmann equation.
Department of Mathematics, Chalmers University of Technology, S-41296 Göteborg, Sweden
719
Håkan Andréasson
author
Andréasson
Håkan
lrr-2014-2-u1
Minor update. Added 13 new references. More accurate quotations on spins. Minor improvements in wording. Added new PN subdominant gravitational-wave modes and SF comparisons.
2016-01-12
2016-01-15
update
lrr-2013-4
Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
Relativistic Binaries in Globular Clusters
2013LRR....16....4B
4
2012-11-29
2011-10-16
2013-03-04
Substantial revision of most sections. Addition of Jonathan Downing as co-author. Number of references increased from 247 to 495.
16
Black holes
Gravitational wave sources
Globular clusters
Binary systems
Accretion disks
Pulsars
publication
lorimer.duncan
My research interests include radio astronomy, compact objects, signal processing and numerical simulations of stellar populations. I am particularly interested in studies of pulsars - rapidly rotating highly magnetized neutron stars.
West Virginia University, Department of Physics, PO Box 6415, Morgantown, WV 26506, U.S.A.
678
Duncan R. Lorimer
author
Lorimer
Duncan R.
lrr-2010-5-maartens.roy
authorOrder
1
lrr-2012-7-lopes-costa.joao
authorOrder
2
lrr-2012-1
A priori, there is nothing very special about shear-free or asymptotically shear-free null geodesic congruences. Surprisingly, however, they turn out to possess a large number of fascinating geometric properties and to be closely related, in the context of general relativity, to a variety of physically significant effects. It is the purpose of this paper to try to fully develop these issues.
This work starts with a detailed exposition of the theory of shear-free and asymptotically shear-free null geodesic congruences, i.e., congruences with shear that vanishes at future conformal null infinity. A major portion of the exposition lies in the analysis of the space of regular shear-free and asymptotically shear-free null geodesic congruences. This analysis leads to the space of complex analytic curves in an auxiliary four-complex dimensional space, ℋ-space. They in turn play a dominant role in the applications.
The applications center around the problem of extracting interior physical properties of an asymptotically-flat spacetime directly from the asymptotic gravitational (and Maxwell) field itself, in analogy with the determination of total charge by an integral over the Maxwell field at infinity or the identification of the interior mass (and its loss) by (Bondi's) integrals of the Weyl tensor, also at infinity.
More specifically, we will see that the asymptotically shear-free congruences lead us to an asymptotic definition of the center-of-mass and its equations of motion. This includes a kinematic meaning, in terms of the center-of-mass motion, for the Bondi three-momentum. In addition, we obtain insights into intrinsic spin and, in general, angular momentum, including an angular-momentum--conservation law with well-defined flux terms. When a Maxwell field is present, the asymptotically shear-free congruences allow us to determine/define at infinity a center-of-charge world line and intrinsic magnetic dipole moment.
Null Geodesic Congruences, Asymptotically-Flat Spacetimes and Their Physical Interpretation
2012LRR....15....1A
1
2012-01-16
2011-06-23
2012-01-23
These revisions were done exclusively by Adamo and Newman, therefore the author order was slightly changed. There was nothing essentially wrong in the earlier version, but we have included several new results (in the text and in appendices), corrected an error of interpretation in Section 7, and (the main reason for the revision) we found much easier ways of doing some of the long calculations with very much simpler arguments. 19 new references were added.
15
Spin-coefficient formalism
Asymptotic flatness
H-space
Shear-free congruences
publication
chrusciel.piotr
Global structure of solutions of Einstein equations, Global Lorentzian geometry, General relativistic constraint equations, Mass in general relativity, Classification of black hole space-times, Nonlinear partial differential equations
University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
Piotr T. Chruściel
author
Chruściel
Piotr T.
hough.jim
Gravitational Wave Detection on ground (GEO 600 and Advanced LIGO) and in space (LISA); ultra stable lasers, ultra sensitive mechanical systems, and investigation of materials of ultra-low mechanical loss.
Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.
180
James Hough
author
Hough
James
lrr-1998-12
Gravitational Lensing in Astronomy
1998LRR.....1...12W
Deflection of light by gravity was predicted by General Relativity and observationally confirmed in 1919. In the following decades, various aspects of the gravitational lens effect were explored theoretically. Among them were: the possibility of multiple or ring-like images of background sources, the use of lensing as a gravitational telescope on very faint and distant objects, and the possibility of determining Hubble's constant with lensing. It is only relatively recently, (after the discovery of the first doubly imaged quasar in 1979), that gravitational lensing has became an observational science. Today lensing is a booming part of astrophysics.
In addition to multiply-imaged quasars, a number of other aspects of lensing have been discovered: For example, giant luminous arcs, quasar microlensing, Einstein rings, galactic microlensing events, arclets, and weak gravitational lensing. At present, literally hundreds of individual gravitational lens phenomena are known.
Although still in its childhood, lensing has established itself as a very useful astrophysical tool with some remarkable successes. It has contributed significant new results in areas as different as the cosmological distance scale, the large scale matter distribution in the universe, mass and mass distribution of galaxy clusters, the physics of quasars, dark matter in galaxy halos, and galaxy structure. Looking at these successes in the recent past we predict an even more luminous future for gravitational lensing.
12
1998-08-28
1998-11-02
1
publication
kunduri.hari
Mathematical and theoretical aspects of black holes, within the framework of general relativity and its extensions in string theory
Department of Mathematics and Statistics, Memorial University of Newfoundland, St John's NL A1C 4P5, Canada
Hari K. Kunduri
author
Kunduri
Hari K.
lrr-2000-3-rowan.sheila
authorOrder
1
lrr-2005-4-tinto.massimo
authorOrder
1
turyshev.slava
Science motivation, mission design, and data analysis of high precision gravitational experiments in space
Relativistic cosmology and alternative theories of gravity; theory of gravity-wave astronomy, including wave generation, propagation and detection
Theory of and modeling for high precision astronomical reference frames; lunar and interplanetary laser ranging; pulsar timing experiments;
Optimization and control algorithms for long-baseline optical interferometry; analytical and numerical techniques for the white-light fringe parameter estimation
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, U.S.A.
Slava G. Turyshev
author
Turyshev
Slava G.
psaltis.dimitrios
My research focuses on the physics of neutron stars and black holes, the properties of magnetohydrodynamic turbulence in accretion flows, the testing of the theory of general relativity in the strong-field regime, and the physics responsible for the accelerating universe. I routinely solve problems that involve hydrodynamics and photon transport in extreme physical conditions, using both analytical and numerical tools.
Physics and Astronomy Departments, University of Arizona, Tucson, AZ 85721, U.S.A.
Dimitrios Psaltis
author
Psaltis
Dimitrios
lrr-2012-1-newman.ezra
authorOrder
2
lrr-2014-1
The Hole Argument and Some Physical and Philosophical Implications
2012-11-11
2014LRR....17....1S
This is a historical-critical study of the hole argument, concentrating on the interface between historical, philosophical and physical issues. Although it includes a review of its history, its primary aim is a discussion of the contemporary implications of the hole argument for physical theories based on dynamical, background-independent space-time structures.
The historical review includes Einstein’s formulations of the hole argument, Kretschmann’s critique, as well as Hilbert’s reformulation and Darmois’ formulation of the general-relativistic Cauchy problem. The 1970s saw a revival of interest in the hole argument, growing out of attempts to answer the question: Why did three years elapse between Einstein’s adoption of the metric tensor to represent the gravitational field and his adoption of the Einstein field equations?
The main part presents some modern mathematical versions of the hole argument, including both coordinate-dependent and coordinate-independent definitions of covariance and general covariance; and the fiber bundle formulation of both natural and gauge natural theories. By abstraction from continuity and differentiability, these formulations can be extended from differentiable manifolds to any set; and the concepts of permutability and general permutability applied to theories based on relations between the elements of a set, such as elementary particle theories.
We are closing with an overview of current discussions of philosophical and physical implications of the hole argument.
1
2013-11-17
2014-02-06
17
General relativity
History of science
Philosophy of science
publication
fryer.chris
Los Alamos National Laboratory, MS D409, CCS-2, Los Alamos, NM 87545, U.S.A.
Chris L. Fryer
author
Fryer
Chris L.
forkel
ePublishing Toolkit Programming & Server Admin (2002-2011)
Robert Forkel
teamMember
e
Forkel
Robert
lrr-1998-6
Stationary Black Holes: Uniqueness and Beyond
1998LRR.....1....6H
The spectrum of known black hole solutions to the stationary Einstein equations has increased in an unexpected way during the last decade. In particular, it has turned out that not all black hole equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black hole space-times ceases to exist in self-gravitating non-linear field theories. This text aims to review some of the recent developments and to discuss them in the light of the uniqueness theorem for the Einstein-Maxwell system.
6
1998-04-15
1998-05-08
1
self-gravitating classical fields
uniqueness theorems
black holes
publication
rendall.alan
Spacetime singularities, cosmic censorship, mathematical justification of methods used in gravitational physics, applications of the theory of partial differential equations to the Einstein equations.
Max-Planck-Institut für Gravitationsphysik, Am Mühlenberg 1, D-14424 Golm, Germany
795
Alan D. Rendall
author
Rendall
Alan D.
lrr-2010-1
Interferometer Techniques for Gravitational-Wave Detection
2009-09-21
2010LRR....13....1F
Several km-scale gravitational-wave detectors have been constructed world wide. These instruments combine a number of advanced technologies to push the limits of precision length measurement. The core devices are laser interferometers of a new kind; developed from the classical Michelson topology these interferometers integrate additional optical elements, which significantly change the properties of the optical system. Much of the design and analysis of these laser interferometers can be performed using well-known classical optical techniques, however, the complex optical layouts provide a new challenge. In this review we give a textbook-style introduction to the optical science required for the understanding of modern gravitational wave detectors, as well as other high-precision laser interferometers. In addition, we provide a number of examples for a freely available interferometer simulation software and encourage the reader to use these examples to gain hands-on experience with the discussed optical methods.
1
2010-02-15
2010-02-25
13
Optics
Gravitational waves
Finesse
Interferometer simulations
Gravitational wave detectors
Laser interferometry
publication
hu.bei-lok
Gravitation and Cosmology, Quantum Field Theory in Curved Spacetime, Quantum Processes in the Early Universe, Nonequilibrium Statistical Field Theory, Foundational Issues of Quantum Mechanics, Theoretical Aspects of Quantum and Atom Optics
Department of Physics, University of Maryland, College Park, Maryland 20742-4111, U.S.A.
982
Bei Lok Hu
author
Hu
Bei Lok
lrr-2011-7
This review is concerned with the motion of a point scalar charge, a point electric charge, and a point mass in a specified background spacetime. In each of the three cases the particle produces a field that behaves as outgoing radiation in the wave zone, and therefore removes energy from the particle. In the near zone the field acts on the particle and gives rise to a self-force that prevents the particle from moving on a geodesic of the background spacetime. The self-force contains both conservative and dissipative terms, and the latter are responsible for the radiation reaction. The work done by the self-force matches the energy radiated away by the particle.
The field's action on the particle is difficult to calculate because of its singular nature: the field diverges at the position of the particle. But it is possible to isolate the field's singular part and show that it exerts no force on the particle -- its only effect is to contribute to the particle's inertia. What remains after subtraction is a regular field that is fully responsible for the self-force. Because this field satisfies a homogeneous wave equation, it can be thought of as a free field that interacts with the particle; it is this interaction that gives rise to the self-force.
The mathematical tools required to derive the equations of motion of a point scalar charge, a point electric charge, and a point mass in a specified background spacetime are developed here from scratch. The review begins with a discussion of the basic theory of bitensors (Part I). It then applies the theory to the construction of convenient coordinate systems to chart a neighbourhood of the particle's word line (Part II). It continues with a thorough discussion of Green's functions in curved spacetime (Part III). The review presents a detailed derivation of each of the three equations of motion (Part IV). Because the notion of a point mass is problematic in general relativity, the review concludes (Part V) with an alternative derivation of the equations of motion that applies to a small body of arbitrary internal structure.
The Motion of Point Particles in Curved Spacetime
2011LRR....14....7P
7
2011-08-23
2011-02-02
2011-09-29
This version of the review is a major update of the original article published in 2004. Two additional authors, Adam Pound and Ian Vega, have joined the article's original author, and each one has contributed a major piece of the update. The literature survey presented in Sections 2 was contributed by Ian Vega, and Part V (Sections 20 to 23) was contributed by Adam Pound. Part V replaces a section of the 2004 article in which the motion of a small black hole was derived by the method of matched asymptotic expansions; this material can still be found in Ref. [142], but Pound's work provides a much more satisfactory foundation for the gravitational self-force. The case study of Section 1.10 is new, and the ''exact'' formulation of the dynamics of a point mass in Section 19.1 is a major improvement from the original article. The concluding remarks of Section 24, contributed mostly by Adam Pound, are also updated from the 2004 article. The number of references has increased from 64 to 187.
14
gravitation
equations of motion
point particles
self force
curved spacetime
scalar field
electromagnetic field
radiation reaction
publication
cardoso.vitor
I lead the gravity team in CENTRA/IST and we are doing exciting things: trying to understand black hole dynamics in generic spacetimes, specifically higher-dimensional and asymptotically anti-de Sitter spacetimes; trying to discriminate between different gravity theories using gravitational-wave observations…and in general doing General Relativity and black hole physics.
CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049 Lisboa, Portugal and Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
Vítor Cardoso
author
Cardoso
Vítor
lrr-2008-5
The problem of describing the quantum behavior of gravity, and thus understanding quantum spacetime, is still open. Loop quantum gravity is a well-developed approach to this problem. It is a mathematically well-defined background-independent quantization of general relativity, with its conventional matter couplings. Today research in loop quantum gravity forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained so far are: (i) The computation of the spectra of geometrical quantities such as area and volume, which yield tentative quantitative predictions for Planck-scale physics. (ii) A physical picture of the microstructure of quantum spacetime, characterized by Planck-scale discreteness. Discreteness emerges as a standard quantum effect from the discrete spectra, and provides a mathematical realization of Wheeler’s “spacetime foam” intuition. (iii) Control of spacetime singularities, such as those in the interior of black holes and the cosmological one. This, in particular, has opened up the possibility of a theoretical investigation into the very early universe and the spacetime regions beyond the Big Bang. (iv) A derivation of the Bekenstein–Hawking black-hole entropy. (v) Low-energy calculations, yielding n-point functions well defined in a background-independent context. The theory is at the roots of, or strictly related to, a number of formalisms that have been developed for describing background-independent quantum field theory, such as spin foams, group field theory, causal spin networks, and others. I give here a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.
Loop Quantum Gravity
2008LRR....11....5R
5
2008-05-31
2008-04-28
2008-07-15
Substantially rewritten version of the original article. Changes include figures and updated references (increased from 217 to 300).
11
Quantum gravity, Loop quantum gravity
publication
lrr-2014-4
The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein’s equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse–Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.
The Confrontation between General Relativity and Experiment
2014LRR....17....4W
4
2014-06-06
2014-03-26
2014-06-11
Major revision, updated and expanded. Added new Section 2.3.3 on the Pioneer anomaly; split former Section 3 into new 3 and 4, and extended Section 3.3 on competing theories of gravity; added new Sections 5.3 and 5.4 on compact binary systems; added a new Section 8 on astrophysical and cosmological tests. The number of references increased from 299 to 454. Added two figures (8, 9) and updated Figures 1, 3, 5, and 7.
17
Gravitational radiation
Tests of relativistic gravity
Post-Newtonian limit
Theories of gravity
publication
rovelli.carlo
The center of my research interest is in quantum gravity.
Centre de Physique Théorique de Luminy, Case 907, Luminy, F-13288 Marseille, France
669
Carlo Rovelli
author
Rovelli
Carlo
jackson.neal
Gravitational Lensing
Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Turing Building, Manchester M13 9PL, U.K.
Neal Jackson
author
Jackson
Neal
ashtekar.abhay
Quantum Gravity, General Relativity, Gauge Theories, Geometry and Physics, Buddhist world-view
Institute for Gravitational Physics and Geometry, Pennsylvania State University, University Park, PA 16801, U.S.A. and Kavli Institute of Theoretical Physics, University of California, Santa Barbara, CA 93106-4030, U.S.A. and Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, 14476 Golm, Germany and Erwin-Schrödinger-Institut, Boltzmanngasse 9, 1090 Vienna, Austria
10
Abhay Ashtekar
author
Ashtekar
Abhay
armstrong.john
Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 238-725, 4800 Oak Grove Dr., Pasadena, CA 91109-8001, U.S.A.
John W. Armstrong
author
Armstrong
John W.
lrr-2000-4
Conformal Infinity
The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, "conformal infinity" is related with almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this conceptgradually and inevitably evolved out of physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation and how it lends itself very naturally to solve radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.
4
2000-05-12
2000-08-23
3
publication
newman.ezra
My research is centered on general relativity – the Einstein equations for gravity. More precisely I am interested in properties and the behavior of light-rays in the presence of gravitational fields and how the gravitational field can be reconstructed from the properties of the the light-rays.
Department of Physics and Astronomy, University of Pittsburgh, U.S.A.
Ezra T. Newman
author
Newman
Ezra T.
lrr-2003-6-u1
2010-08-24
2010-09-14
The main changes are new Sections 4.6, 5.3, 5.8, and 5.9, which show the progress since 2003. Added 46 new references.
update
loll
Radboud University, The Netherlands
Renate Loll
ebMember
loll
Loll
Renate
lrr-2016-1
Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo
2013-05-17
2016LRR....19....1A
We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg^2 to 20 deg^2 will require at least three detectors of sensitivity within a factor of ~2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.
1
2016-01-22
2016-02-08
19
Data analysis
Gravitational waves
Gravitational-wave detectors
Electromagnetic counterparts
publication
taniguchi.keisuke
Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
Keisuke Taniguchi
author
Taniguchi
Keisuke
siemens.xavier
I am interested mostly in gravitational-wave astrophysics, early-universe cosmology, especially cosmic strings, and biophysics. I also work on calibration of LIGO data, which is experimentalist work.
Center for Gravitation, Cosmology, and Astrophysics, Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
Xavier Siemens
author
Siemens
Xavier
lrr-2013-5
Quantum-Spacetime Phenomenology
2012-12-05
2013LRR....16....5A
I review the current status of phenomenological programs inspired by quantum-spacetime research. I stress in particular the significance of results establishing that certain data analyses provide sensitivity to effects introduced genuinely at the Planck scale. My main focus is on phenomenological programs that affect the directions taken by studies of quantum-spacetime theories.
5
2013-05-18
2013-06-12
16
Loop quantum gravity
Quantum spacetime
Spacetime noncommutativity
publication
lrr-2006-5
The Asymptotic Safety Scenario in Quantum Gravity
2006-10-05
2006LRR.....9....5N
The asymptotic safety scenario in quantum gravity is reviewed, according to which a renormalizable quantum theory of the gravitational field is feasible which reconciles asymptotically safe couplings with unitarity. The evidence from symmetry truncations and from the truncated flow of the effective average action is presented in detail. A dimensional reduction phenomenon for the residual interactions in the extreme ultraviolet links both results. For practical reasons the background effective action is used as the central object in the quantum theory. In terms of it criteria for a continuum limit are formulated and the notion of a background geometry self-consistently determined by the quantum dynamics is presented. Self-contained appendices provide prerequisites on the background effective action, the effective average action, and their respective renormalization flows.
5
2006-10-23
2006-12-01
9
quantum gravity
publication
will
University of Florida, USA
Clifford Will
ebMember
will
Will
Clifford M.
lrr-2003-7
This review is concerned with a discussion of numerical methods for the solution of the equations of special relativistic hydrodynamics (SRHD). Particular emphasis is put on a comprehensive review of the application of high-resolution shock-capturing methods in SRHD. Results of a set of demanding test bench simulations obtained with different numerical SRHD methods are compared. Three applications (astrophysical jets, gamma-ray bursts and heavy ion collisions) of relativistic flows are discussed. An evaluation of various SRHD methods is presented, and future developments in SRHD are analyzed involving extension to general relativistic hydrodynamics and relativistic magneto-hydrodynamics. The review further provides FORTRAN programs to compute the exact solution of a 1D relativistic Riemann problem with zero and nonzero tangential velocities, and to simulate 1D relativistic flows in Cartesian Eulerian coordinates using the exact SRHD Riemann solver and PPM reconstruction.
Numerical Hydrodynamics in Special Relativity
6
2003LRR.....6....7M
7
2003-12-15
2003-12-19
Article revision.
Section 1: reorganized and slightly modified
Section 2.3: completely changed to discuss the exact solution of the Riemann problem in the more general case of arbitrary tangential velocities; Fig. 2 replaced; Figs. 3, 4 and Table 1: new
Section 6.2.1: discussion expanded; Tables 8, 9 and 10 (orig. 6, 7 and 8) expanded; Fig. 8 new
Section 7.1: (Applications: Astrophysical jets): updated (new figures and movies)
Section 7.2: (Applications: GRBs): updated (new figures and movies)
Section 7.3: (Relativistic Heavy Ion Collisions): new
Section 8.1: (Evaluation of the methods): discussion updated; Table 12 (orig. Table 10) updated
Section 8.2: (Present and future developments): substantially modified
Section 9.1: (Incorporation of complex EOS): new
Source codes: (Programs RIEMANN_VT and RPPM): new
References: Number has increased from 198 to 308
publication
haensel.pawel
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warszawa, Poland
Paweł Haensel
author
Haensel
Paweł
jones.aled
climate finance, energy and behaviour, and resource management
Global Sustainability Institute (GSI) at Anglia Ruskin University
865
Aled Jones
author
Jones
Aled
lrr-2005-4-dhurandhar.sanjeev
authorOrder
2
mcgaugh.stacy
Low surface brightness galaxies, Galaxy formation and evolution, Tests of dark matter and alternative hypotheses, Measurements of cosmological parameters
Department of Astronomy, University of Maryland, USA and Case Western Reserve University, USA
Stacy S. McGaugh
author
McGaugh
Stacy S.
lrr-2004-4-u1
Recent developments of the field are included. 16 new references are added, minor improvements and corrections of the text are made at several points, and the bibliography is updated.
2005-03-23
2005-06-01
update
lrr-2009-1-u1
Corrected typos in Equations (62) and (64). Added DOIs and updated format of references, thereby reducing PDF page numbers from 107 to 103.
2012-01-23
2012-01-23
update
heusler.markus
My field of research is general relativity. In particular, my scientific activities include the theory of black holes and the interaction of gravity with nonlinear field theories.
ITP, University of Zurich, CH-8057 Zurich, Switzerland
790
Markus Heusler
author
Heusler
Markus
barbero.fernando
Classical and quantum general relativity and mathematical physics.
Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid, Spain
J. Fernando Barbero G.
author
Barbero G.
J. Fernando
visser.matt
I am currently engaged in several major research projects. The technical thrust of these projects can be summarized as 'field theory under unusual conditions', and the potential applications run all the way from basic quantum physics to cosmology and quantum gravity.
School of Mathematics, Statistics, and Computer Science, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
Matt Visser
author
Visser
Matt
loll.renate
Theory of quantum gravity.
Institute for Mathematics, Astrophysics and Particle Physics, Faculty of Science, Radboud University Nijmegen
792
Renate Loll
author
Loll
Renate
krishnan.badri
Classical general relativity. Mathematical aspects of black hole physics with applications to numerical relativity. Gravitational wave data analysis and gravitational wave astrophysics.
Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, 14476 Golm, Germany and Erwin-Schrödinger-Institut, Boltzmanngasse 9, 1090 Vienna, Austria
996
Badri Krishnan
author
Krishnan
Badri
frauendiener.joerg
Computational and gravitational physics. In particular: Gravitational waves, Conformal field equations and asymptotic structure, Initial boundary value problems for Einstein's field equations
Department of Mathematics and Statistics, University of Otago, P.O. Box 56, Dunedin 9010, New Zealand
818
Jörg Frauendiener
author
Frauendiener
Jörg
lrr-2011-5
Significant progress has been made in recent years on the development of gravitational-wave detectors. Sources such as coalescing compact binary systems, neutron stars in low-mass X-ray binaries, stellar collapses and pulsars are all possible candidates for detection. The most promising design of gravitational-wave detector uses test masses a long distance apart and freely suspended as pendulums on Earth or in drag-free spacecraft. The main theme of this review is a discussion of the mechanical and optical principles used in the various long baseline systems in operation around the world - LIGO (USA), Virgo (Italy/France), TAMA300 and LCGT (Japan), and GEO600 (Germany/U.K.) - and in LISA, a proposed space-borne interferometer. A review of recent science runs from the current generation of ground-based detectors will be discussed, in addition to highlighting the astrophysical results gained thus far. Looking to the future, the major upgrades to LIGO (Advanced LIGO), Virgo (Advanced Virgo), LCGT and GEO600 (GEO-HF) will be completed over the coming years, which will create a network of detectors with the significantly improved sensitivity required to detect gravitational waves. Beyond this, the concept and design of possible future "third generation" gravitational-wave detectors, such as the Einstein Telescope (ET), will be discussed.
Gravitational Wave Detection by Interferometry (Ground and Space)
2011LRR....14....5P
5
2011-06-17
2011-02-16
2011-07-11
For the update the author list has changed to be Matthew Pitkin, Stuart Reid, Sheila Rowan and Jim Hough. There have been minor updates to Sections 1, 2 and 3; major updates to Sections 4 and 5; Section 6 has been renamed and includes entirely new material on the operation of, and results from, the first generation of gravitational wave detectors and upgrades that are under way; and Section 7 also includes major updates about the status of LISA. The number of references has increased from 110 to 324.
14
Gravitational waves
Noise sources
Science runs
Data analysis
Gravitational wave detectors
Interferometric gravitational wave detectors
Laser interferometry
publication
merritt.david
Supermassive black holes, galactic and stellar dynamics, dark matter, inverse problems in dynamical astronomy, and non-integrable galactic dynamics.
Center for Computational Relativity and Gravitation (CCRG), Rochester Institute of Technology, Rochester, NY, U.S.A.
David Merritt
author
Merritt
David
lrr-2011-5-pitkin.matthew
authorOrder
1
bojowald.martin
Loop quantum gravity and cosmology, spin foam models, cosmological singularities, early universe phenomenology, symmetry reduced models of (quantum) gravity, black holes; Poisson sigma models and Poisson geometry, and non-commutative geometry from string theory.
Institute for Gravitational Physics and Geometry, The Pennsylvania State University, University Park, PA 16802, U.S.A.
Martin Bojowald
author
Bojowald
Martin
lopes-costa.joao
General relativity, geometrical analysis and differential games
Instituto Universitário de Lisboa (ISCTE-IUL), Lisboa, Portugal and Centro de Análise Matemática, Geometria e Sistemas Dinâmicos, Instituto Superior Técnico, Universidade Técnica de Lisboa, Portugal
João Lopes Costa
author
Costa
João
herdeiro.carlos
Black hole physics, General relativity, numerical relativity and gravitational radiation, Supergravity, string theories and the gauge/gravity duality, Differential geometry, Casimir effect and quantum field theory, Cosmology and inflationary models
Departamento de Física da Universidade de Aveiro and CIDMA, Campus de Santiago, 3810-183 Aveiro, Portugal
Carlos A. R. Herdeiro
author
Herdeiro
Carlos A. R.
lrr-2008-1
Spacelike Singularities and Hidden Symmetries of Gravity
2008-02-05
2008LRR....11....1H
We review the intimate connection between (super-)gravity close to a spacelike singularity (the “BKL-limit”) and the theory of Lorentzian Kac-Moody algebras. We show that in this limit the gravitational theory can be reformulated in terms of billiard motion in a region of hyperbolic space, revealing that the dynamics is completely determined by a (possibly infinite) sequence of reflections, which are elements of a Lorentzian Coxeter group. Such Coxeter groups are the Weyl groups of infinite-dimensional Kac-Moody algebras, suggesting that these algebras yield symmetries of gravitational theories. Our presentation is aimed to be a self-contained and comprehensive treatment of the subject, with all the relevant mathematical background material introduced and explained in detail. We also review attempts at making the infinite-dimensional symmetries manifest, through the construction of a geodesic sigma model based on a Lorentzian Kac-Moody algebra. An explicit example is provided for the case of the hyperbolic algebra E_10, which is conjectured to be an underlying symmetry of M-theory. Illustrations of this conjecture are also discussed in the context of cosmological solutions to eleven-dimensional supergravity.
1
2008-02-12
2008-04-24
11
hidden symmetries, duality, Kac-Moody algebras
publication
dimmelmeier
Technical & Scientific Editor (1999-2008)
Harald Dimmelmeier
teamMember
g
Dimmelmeier
Harald
baker.john
Gravitational Astrophysics Lab, NASA Goddard Space Flight Center, 8800 Greenbelt Rd., Greenbelt, MD 20771, USA
John G. Baker
author
Baker
John G.
lrr-2005-3-u1
2007-07-24
2007-07-26
Section 2 and 4.4.1 have been extended, some notations were changed and Figure 1 was updated. Equations (28) and (36) have been corrected. 15 references were added.
update
tinto.massimo
Gravitational Radiation, Classical General Relativity, Exact Solutions, Experimental Tests of Relativistic Gravity
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, U.S.A. and LIGO Laboratory, California Institute of Technology, Pasadena, CA 91125, U.S.A.
Massimo Tinto
author
Tinto
Massimo
lrr-2012-5
Quantum Measurement Theory in Gravitational-Wave Detectors
2011-07-06
2012LRR....15....5D
The fast progress in improving the sensitivity of the gravitational-wave detectors, we all have witnessed in the recent years, has propelled the scientific community to the point at which quantum behavior of such immense measurement devices as kilometer-long interferometers starts to matter. The time when their sensitivity will be mainly limited by the quantum noise of light is around the corner, and finding ways to reduce it will become a necessity. Therefore, the primary goal we pursued in this review was to familiarize a broad spectrum of readers with the theory of quantum measurements in the very form it finds application in the area of gravitational-wave detection. We focus on how quantum noise arises in gravitational-wave interferometers and what limitations it imposes on the achievable sensitivity. We start from the very basic concepts and gradually advance to the general linear quantum measurement theory and its application to the calculation of quantum noise in the contemporary and planned interferometric detectors of gravitational radiation of the first and second generation. Special attention is paid to the concept of the Standard Quantum Limit and the methods of its surmounting.
5
2012-03-02
2012-04-26
15
standard quantum limit
quantum non-demolition measurement
quantum measurement theory
filter cavities
gravitational-wave detectors
quantum speed meter
squeezed light
quantum noise
back-action evasion
optical rigidity
publication
seidel
National Center for Supercomputing Applications, USA
Edward Seidel
ebMember
seidel
Seidel
Edward
bruegmann
Friedrich Schiller University, Jena, Germany
Bernd Brügmann
ebMember
bruegmann
Brügmann
Bernd
mueller.ewald
Cosmological Perturbations, Brane-World Gravity, Cosmological Dynamics
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching, Germany
680
Ewald Müller
author
Müller
Ewald
lrr-1998-10
Binary and Millisecond Pulsars
Our knowledge of binary and millisecond pulsars has greatly increased in recent years. This is largely due to the success of large-area surveys which have brought the known population of such systems in the Galactic disk to around 50. As well as being interesting as a population of astronomical sources, many pulsars turn out to be superb celestial clocks. In this review we summarise the main properties of binary and millisecond pulsars and highlight some of their applications to relativistic astrophysics.
10
1998-08-28
1998-09-25
1
pulsars -- general
publication
perlick.volker
My research interests are subjects from classical general relativity, in particular applications from Lorentzian geometry, e.g. variational problems for geodesics, geometry of wave fronts, and related subjects with relevance to gravitational lensing.
Physics Department, Lancaster University, Lancaster, LA1 4YB, U.K.
562
Volker Perlick
author
Perlick
Volker
stairs.ingrid
My work involves the observation of radio pulsars and their companions, with a general theme of studying binary pulsar evolution, and with sidelines in such areas as pulsar instrumentation and polarimetry, and some higher-frequency observations.
Dept. of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
942
Ingrid H. Stairs
author
Stairs
Ingrid H.
lrr-2007-5-u1
2010-02-22
2010-02-23
Added summaries of papers which have appeared since the last version of 2007 (17 new references have been added.).
update
lrr-2006-4
The article reviews the current status of a theoretical approach to the problem of the emission of gravitational waves by isolated systems in the context of general relativity. Part A of the article deals with general post-Newtonian sources. The exterior field of the source is investigated by means of a combination of analytic post-Minkowskian and multipolar approximations. The physical observables in the far-zone of the source are described by a specific set of radiative multipole moments. By matching the exterior solution to the metric of the post-Newtonian source in the near-zone we obtain the explicit expressions of the source multipole moments. The relationships between the radiative and source moments involve many non-linear multipole interactions, among them those associated with the tails (and tails-of-tails) of gravitational waves. Part B of the article is devoted to the application to compact binary systems. We present the equations of binary motion, and the associated Lagrangian and Hamiltonian, at the third post-Newtonian (3PN) order beyond the Newtonian acceleration. The gravitational-wave energy flux, taking consistently into account the relativistic corrections in the binary moments as well as the various tail effects, is derived through 3.5PN order with respect to the quadrupole formalism. The binary's orbital phase, whose prior knowledge is crucial for searching and analyzing the signals from inspiralling compact binaries, is deduced from an energy balance argument.
Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries
2006LRR.....9....4B
4
2006-05-16
2006-04-27
2006-06-01
Updated article and added 65 references. Included new sections 5.5, 8.3, 8.4, 9.4, 9.5, and 9.6.
9
gravitational radiation, post-Newtonian approximation, multipolar expansion, inspiralling compact binary
publication
marolf
University of California, Santa Barbara, USA
Donald Marolf
ebMember
marolf
Marolf
Donald
lrr-2006-2-u1
2008-06-30
2008-06-30
Added 16 new references and latest observations.
update
lrr-2014-6
Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers), the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI).
This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA) mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.
Time-Delay Interferometry
2014LRR....17....6T
6
2014-07-28
2014-02-25
2014-08-05
Major revision, updated and expanded. The number of references increased from 35 to 65. This revised version includes new and major theoretical and experimental results that have appeared in the literature since the original review got released. The new Section 5.3 covers recent work performed by S.V.D. and collaborators on the mathematical foundations of second-generation TDI. Section 5.4 instead addresses the derivation of the TDI space corresponding to a laser interferometer architecture with only two arms. This covers both the LISA mission in the eventuality of failure of one of its arms, or other mission concepts in which by design only two arms are envisioned. Finally, in Section 7 some practical and experimental aspects related to the performance specifications of the different subsystems used for implementing TDI have been included.
17
Gravitational-wave detectors
Interferometry
publication
bishop.nigel
Department of Mathematics, Rhodes University, PO Box 94, 6140 Grahamstown, South Africa
Nigel T. Bishop
author
Bishop
Nigel T.
lrr-2002-5
Perturbative Quantum Gravity and its Relation to Gauge Theory
2002LRR.....5....5B
In this review we describe a non-trivial relationship between perturbative gauge theory and gravity scattering amplitudes. At the semi-classical or tree-level, the scattering amplitudes of gravity theories in flat space can be expressed as a sum of products of well defined pieces of gauge theory amplitudes. These relationships were first discovered by Kawai, Lewellen, and Tye in the context of string theory, but hold more generally. In particular, they hold for standard Einstein gravity. A method based on $D$-dimensional unitarity can then be used to systematically construct all quantum loop corrections order-by-order in perturbation theory using as input thegravity tree amplitudes expressed in terms of gauge theory ones. More generally, the unitarity method provides a means for perturbatively quantizing massless gravity theories without the usual formal apparatus associated with the quantization of constrained systems. As one application, this method was used to demonstrate that maximally supersymmetric gravity is less divergent in the ultraviolet than previously thought.
5
2002-07-12
2002-07-31
5
supergravity
gauge theory
quantum gravity
publication
lrr-2010-7
Tests of Gravity Using Lunar Laser Ranging
2010-03-14
2010LRR....13....7M
Lunar laser ranging (LLR) has been a workhorse for testing general relativity over the past four decades. The three retroreflector arrays put on the Moon by the Apollo astronauts and the French built arrays on the Soviet Lunokhod rovers continue to be useful targets, and have provided the most stringent tests of the Strong Equivalence Principle and the time variation of Newton’s gravitational constant. The relatively new ranging system at the Apache Point 3.5 meter telescope now routinely makes millimeter level range measurements. Incredibly, it has taken 40 years for ground station technology to advance to the point where characteristics of the lunar retroreflectors are limiting the precision of the range measurements. In this article, we review the gravitational science and technology of lunar laser ranging and discuss prospects for the future.
7
2010-09-30
2010-11-02
13
General relativity
Tests of relativity
publication
lrr-2003-6
Analytic Black Hole Perturbation Approach to Gravitational Radiation
2003LRR.....6....6S
We review the analytic methods used to perform the post-Newtonian expansion of gravitational waves induced by a particle orbiting a massive, compact body, based on black hole perturbation theory. There exist two different methods of performing the post-Newtonian expansion. Both are based on the Teukolsky equation. In one method, the Teukolsky equation is transformed into a Regge–Wheeler type equation that reduces to the standard Klein–Gordon equation in the flat-space limit, while in the other method (which was introduced by Mano, Suzuki, and Takasugi relatively recently), the Teukolsky equation is used directly in its original form. The former’s advantage is that it is intuitively easy to understand how various curved space effects come into play. However, it becomes increasingly complicated when one goes to higher and higher post-Newtonian orders. In contrast, the latter’s advantage is that a systematic calculation to higher post-Newtonian orders can be implemented relatively easily, but otherwise, it is so mathematical that it is hard to understand the interplay of higher order terms. In this paper, we review both methods so that their pros and cons may be seen clearly. We also review some results of calculations of gravitational radiation emitted by a particle orbiting a black hole.
6
2003-09-05
2003-11-21
6
Post-Newtonian expansion
Teukolsky equation
publication
lrr-2002-2
Relativistic Binaries in Globular Clusters
2002LRR.....5....2B
The galactic population of globular clusters are old, dense star systems, with a typical cluster containing $10^4 - 10^6$ stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct $N$-body integrations and Fokker--Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.
2
2002-01-28
2002-02-20
5
neutron stars
gravitational wave sources
radio astronomy
astronomical observations
white dwarfs
astronomy
accretion
stars
accretion disks
pulsars
astrophysics
binary systems
dynamical systems
black holes
publication
lrr-1998-8-u1
Section 2.1: changed estimated timescale for enforcement of
uniform rotation of neutron star.
Section 2.4: changed title of subsection 2.4.4 and
attributed minimal surface scheme to Neugebauer and Herold.
Bibliography: added missing author name 'Burderi, L.' to
reference 59.
2001-08-31
update
lrr-2011-5-hough.jim
authorOrder
4
andersson.nils
My main interests concern black holes and neutron stars as gravitational-wave sources, and various other aspects of classical general relativity.
School of Mathematics, University of Southampton, Southampton SO17 1BJ, U.K.
Nils Andersson
author
Andersson
Nils
lrr-2008-4
Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time.
Loop Quantum Cosmology
2008LRR....11....4B
4
2008-05-26
2008-05-23
2008-07-02
Updated and added 108 new references.
New:
Sect. 3.7 on relational dynamics
Sect. 4.7 on phenomenological higher curvature corrections
Sect. 4.8 on their intuitive meaning
Sect. 4.9 on applications
Sect. 4.13 on phenomenological higher curvature in anisotropic models
Sect. 4.14 bottom paragraph on the BKL picture
Sect. 4.19.1 paragraph
Sect. 4.19.5 on cosmological perturbation theory
Sect. 4.19.6 on equations of state
Sect. 4.19.7 on big bang nucleosynthesis
Sect. 4.20 extended summary
Sect. 5.5 on dynamical refinements of the discreteness scale
Sect. 5.20 on numerical and mathematical quantum cosmology
Sect. 6 on effective theory
Sect. 7.1 two bottom paragraphs on symmetric states
Sect. 9 some updates according to recent progress
Systematic changes:
Sect. 4: consider different types of quantum corrections from loop
quantum gravity: inverse volume and holonomies. Emphasize quantum
back-reaction with reference to new Sect. 6
Sect. 4.17: several changes on inhomogeneous perturbations
Sect. 5.4: several remarks added on possible scale dependence of the
discreteness in Hamiltonian constraint operators as well as new
constructions of operators for closed and open models
Sect. 5.6.2: update of procedure to derive effective equations, with
reference to new Sect. 6
Corrections in Sect. 5.11 on Einstein-Rosen waves
11
Ashtekar variables, Big Bang, canonical quantum gravity, cosmology, effective equations, equations of motion, inflation, quantum cosmology, singularities, symmetry, time, difference equations
publication
2005-07-20
lrr-2005-7
We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1700. There are now 80 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 103 pulsars in 24 of the Galactic globular clusters. Recent highlights have been the discovery of the first ever double pulsar system and a recent flurry of discoveries in globular clusters, in particular Terzan 5.
Binary and Millisecond Pulsars
2005LRR.....8....7L
7
2005-10-21
2005-11-09
The 2005 update includes the latest discoveries of double neutron star binaries, including the double-pulsar system J0737-3039. The impact of this binary on the merger rate of these systems is discussed, as well as its uses as a laboratory for testing general relativity in the strong field regime.
Other notable discoveries featured in the article are 28 new pulsars in the globular cluster Terzan 5.
The number of references has increased from 274 to 347.
8
Pulsars
publication
harms.jan
Università degli Studi di Urbino ‘Carlo Bo’, 61029 Urbino, Italy
Jan Harms
author
Harms
Jan
euclid-theory-working-group
Euclid Theory Working Group
author
thornburg.jonathan
My main research interests are in numerical (general) relativity.
Department of Astronomy, Indiana University, Swain West 312, 727 East Third Street, Bloomington, IN 47405, U.S.A.
Jonathan Thornburg
author
Thornburg
Jonathan
lrr-2011-5-rowan.sheila
authorOrder
3
schmidt.bernd
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), D-14476 Golm, Germany
353
Bernd G. Schmidt
author
Schmidt
Bernd G.
lrr-2010-2
Cosmic Censorship for Gowdy Spacetimes
2010-02-18
2010LRR....13....2R
Due to the complexity of Einstein’s equations, it is often natural to study a question of interest in the framework of a restricted class of solutions. One way to impose a restriction is to consider solutions satisfying a given symmetry condition. There are many possible choices, but the present article is concerned with one particular choice, which we shall refer to as Gowdy symmetry. We begin by explaining the origin and meaning of this symmetry type, which has been used as a simplifying assumption in various contexts, some of which we shall mention. Nevertheless, the subject of interest here is strong cosmic censorship. Consequently, after having described what the Gowdy class of spacetimes is, we describe, as seen from the perspective of a mathematician, what is meant by strong cosmic censorship. The existing results on cosmic censorship are based on a detailed analysis of the asymptotic behavior of solutions. This analysis is in part motivated by conjectures, such as the BKL conjecture, which we shall therefore briefly describe. However, the emphasis of the article is on the mathematical analysis of the asymptotics, due to its central importance in the proof and in the hope that it might be of relevance more generally. The article ends with a description of the results that have been obtained concerning strong cosmic censorship in the class of Gowdy spacetimes.
2
2010-03-29
2010-04-13
13
Gowdy models
cosmic censorship
Cauchy problem
publication
lrr-2000-5-u1
Section 2.2: correction on longitudinal operator in Equation (25).
Section 2.3: corrected sign error in grad(K) term in Equation (50),
corrected sign error in grad(K) term and added missing index on divergence in Equation (51).
Bibliography: updated publication information for references 47 and 74.
2001-12-15
update
emparan.roberto
In broad terms, my research aims at the elucidation of problems of quantum gravity, and in particular at developing the interface between string theory and gravity.
Institució Catalana de Recerca i Estudis Avançats (ICREA), and Departament de Física Fonamental, Universitat de Barcelona, Marti i Franquès 1, E-08028 Barcelona, Spain
Roberto Emparan
author
Emparan
Roberto
lrr-2012-8
Binary Neutron Star Mergers
2011-09-14
2012LRR....15....8F
We review the current status of studies of the coalescence of binary neutron star systems. We begin with a discussion of the formation channels of merging binaries and we discuss the most recent theoretical predictions for merger rates. Next, we turn to the quasi-equilibrium formalisms that are used to study binaries prior to the merger phase and to generate initial data for fully dynamical simulations. The quasi-equilibrium approximation has played a key role in developing our understanding of the physics of binary coalescence and, in particular, of the orbital instability processes that can drive binaries to merger at the end of their lifetimes. We then turn to the numerical techniques used in dynamical simulations, including relativistic formalisms, (magneto-)hydrodynamics, gravitational-wave extraction techniques, and nuclear microphysics treatments. This is followed by a summary of the simulations performed across the field to date, including the most recent results from both fully relativistic and microphysically detailed simulations. Finally, we discuss the likely directions for the field as we transition from the first to the second generation of gravitational-wave interferometers and while supercomputers reach the petascale frontier.
8
2012-05-22
2012-07-04
15
General relativity
Neutron stars
Binary neutron stars
Numerical relativity
Coalescing binaries
publication
lrr-2010-6
Quantization of Midisuperspace Models
2010-01-22
2010LRR....13....6B
We give a comprehensive review of the quantization of midisuperspace models. Though the main focus of the paper is on quantum aspects, we also provide an introduction to several classical points related to the definition of these models. We cover some important issues, in particular, the use of the principle of symmetric criticality as a very useful tool to obtain the required Hamiltonian formulations. Two main types of reductions are discussed: those involving metrics with two Killing vector fields and spherically-symmetric models. We also review the more general models obtained by coupling matter fields to these systems. Throughout the paper we give separate discussions for standard quantizations using geometrodynamical variables and those relying on loop-quantum-gravity-inspired methods.
6
2010-09-23
2010-10-14
13
Loop quantum gravity
Midisuperspace
Quantization
Quantum gravity
publication
compere.geoffrey
AdS/CFT correspondence, black holes, string theory, gravity
Physique Théorique et Mathématique, Université Libre de Bruxelles, CP 231, 1050 Bruxelles, Belgium
Geoffrey Compère
author
Compère
Geoffrey
gair.jonathan
My work is in aspects of gravitational physics. In particular, recently I have been working primarily on issues associated with the planned space based gravitational wave detector, LISA.
Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK
Jonathan R. Gair
author
Gair
Jonathan R.
wald.robert
My research mainly has focused upon the theory of quantum phenomena in strong gravitational fields, particularly quantum effects involving black holes and black hole thermodynamics. My interests also span attempts to formulate a quantum theory of gravitation (where no background classical metrical or causal structure of spacetime is present), mathematical investigations of classical general relativity, and applications of general relativity to cosmology and astrophysics (such as gravitational lensing phenomena and gravitational radiation reaction effects).
Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637-1433, U.S.A.
418
Robert M. Wald
author
Wald
Robert M.
lrr-2010-5-koyama.kazuya
authorOrder
2
itoh.yousuke
Equation of motion for extended bodies in general relativity, Post-Newtonian approximation, Gravitational radiation, Search for continuous gravitational waves using LIGO/GEO data
Astronomical Institute, Tohoku University, Sendai 980-8578, Japan
Yousuke Itoh
author
Itoh
Yousuke
mueller.ingo
Technical University Berlin, Thermodynamik, D-10623 Berlin, Germany
794
Ingo Müller
author
Müller
Ingo
khanna
Publishing Editor
Ramon Khanna
Ramon
Khanna
teamMember
abramowicz.marek
As Professor of Astrophysics (Chair) at Göteborg University, I am conducting research on a wide range of subjects: black holes, quasars, neutron stars, gamma ray bursts, gravitational radiation, quantum gravity, accretion discs. My research deals with the extreme conditions of curvature, compactness, density, temperature and strength of gravity typical for high energy astronomical objects. These conditions often reflect fundamental laws of Nature and cannot be even approached in laboratories on Earth.
Physics Department, Göteborg University, SE-412-96 Göteborg, Sweden and N. Copernicus Astronomical Center, Bartycka 18, PL-00-716 Warszawa, Poland
Marek A. Abramowicz
author
Abramowicz
Marek A.
lrr-2008-3
Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein–Langevin equation, which has, in addition, sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued) stress-energy bitensor, which describes the fluctuations of quantum-matter fields in curved spacetimes. A new improved criterion for the validity of semiclassical gravity may also be formulated from the viewpoint of this theory. In the first part of this review we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to the correlation functions. The functional approach uses the Feynman–Vernon influence functional and the Schwinger–Keldysh closed-time-path effective action methods. In the second part, we describe three applications of stochastic gravity. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic-gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, using the Einstein–Langevin equation, we discuss the backreaction of Hawking radiation and the behavior of metric fluctuations for both the quasi-equilibrium condition of a black-hole in a box and the fully nonequilibrium condition of an evaporating black hole spacetime. Finally, we briefly discuss the theoretical structure of stochastic gravity in relation to quantum gravity and point out directions for further developments and applications.
Stochastic Gravity: Theory and Applications
2008LRR....11....3H
3
2008-04-11
2008-01-23
2008-05-29
1. Abstract and sections 1, 2, 4, 5, 7 and 9 revised and updated.
2. Major changes in subsection 3.2
3. New subsection 3.3 on the "Validity of semiclasscal gravity" and the "Large N expansion".
4. New subsection 6.5 on the "Stability of Minkowski spacetime".
5. Major changes in section 8.
6. New subsection 8.3 on "Metric fluctuations of an evaporating black hole".
7. 86 new references.
11
stochastic gravity, semiclassical gravity, quantum gravity, quantum fields in curved space, inflation, structure formation, black holes
publication
lrr-2004-2
On the History of Unified Field Theories
2004LRR.....7....2G
This article is intended to give a review of the history of the classical aspects of unified field theories in the 20th century. It includes brief technical descriptions of the theories suggested, short biographical notes concerning the scientists involved, and an extensive bibliography. The present first installment covers the time span between 1914 and 1933, i.e., when Einstein was living and working in Berlin - with occasional digressions into other periods. Thus, the main theme is the unification of the electromagnetic and gravitational fields augmented by short-lived attempts to include the matter field described by Schrödinger's or Dirac's equations. While my focus lies on the conceptual development of the field, by also paying attention to the interaction of various schools of mathematicians with the research done by physicists, some prosopographical remarks are included.
2
2004-01-14
2004-02-13
7
unified field theories
history of science
publication
mattingly.david
Observational tests of possible Lorentz violation from quantum gravity; Analog models of general relativity; Models of spacetime
Department of Physics, University of California at Davis, Davis, CA 95616, U.S.A.
David Mattingly
author
Mattingly
David
yungelson.lev
Numerical modelling of the evolution of Galaxy binaries
Institute of Astronomy of the Russian Academy of Sciences, 48 Pyatnitskaya Str., 119017 Moscow, Russia
Lev R. Yungelson
author
Yungelson
Lev R.
lrr-2005-8
Massive Black Hole Binary Evolution
2005-09-21
2005LRR.....8....8M
Coalescence of binary supermassive black holes (SBHs) would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers) are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.
8
2005-10-29
2005-11-22
8
publication
lrr-1998-11
The Cosmic Microwave Background
1998LRR.....1...11J
We present a brief review of current theory and observations of the cosmic microwave background (CMB). New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $\Omega$ and $H_\circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.
11
1998-09-29
1998-09-30
1
publication
lrr-2006-1
Low-Frequency Gravitational Wave Searches Using Spacecraft Doppler Tracking
2005-11-29
2006LRR.....9....1A
This paper discusses spacecraft Doppler tracking, the current-generation detector technology used in the low-frequency (~millihertz) gravitational wave band. In the Doppler method the earth and a distant spacecraft act as free test masses with a ground-based precision Doppler tracking system continuously monitoring the earth-spacecraft relative dimensionless velocity $2 \Delta v/c = \Delta \nu/\nu_0$, where $\Delta \nu$ is the Doppler shift and $\nu_0$ is the radio link carrier frequency. A gravitational wave having strain amplitude $h$ incident on the earth-spacecraft system causes perturbations of order $h$ in the time series of $\Delta \nu/\nu_0$. Unlike other detectors, the ~1-10 AU earth-spacecraft separation makes the detector large compared with millihertz-band gravitational wavelengths, and thus times-of-flight of signals and radio waves through the apparatus are important. A burst signal, for example, is time-resolved into a characteristic signature: three discrete events in the Doppler time series. I discuss here the principles of operation of this detector (emphasizing transfer functions of gravitational wave signals and the principal noises to the Doppler time series), some data analysis techniques, experiments to date, and illustrations of sensitivity and current detector performance. I conclude with a discussion of how gravitational wave sensitivity can be improved in the low-frequency band.
1
2005-11-02
2006-01-24
9
Cassini, Doppler stability, Doppler tracking, frequency stability, gravitational wave detectors, radio
publication
lrr-2013-1
Foundations of Black Hole Accretion Disk Theory
2012-06-13
2013LRR....16....1A
This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).
1
2012-11-15
2013-01-14
16
black hole accretion disks
publication
lrr-2006-1-u2
2016-01-06
2016-01-11
New Subsections 4.9, 6.2, and 11 new references were added, 2 were removed.
update
poisson.eric
My research activities have recently been divided into two broad streams. The first stream is concerned with the physics of black holes in tidal environments. The second stream is concerned with the gravitational self-force. The context for this work is provided by the ongoing effort to measure gravitational waves using earth-based detectors (now operational) and space-based detectors (in development).
Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1 and Perimeter Institute for Theoretical Physics, 35 King Street North, Waterloo, Ontario, Canada N2J 2W9
651
Eric Poisson
author
Poisson
Eric
lrr-2008-9
Probes and Tests of Strong-Field Gravity with Observations in the Electromagnetic Spectrum
2008-06-02
2008LRR....11....9P
Neutron stars and black holes are the astrophysical systems with the strongest gravitational fields in the universe. In this article, I review the prospect of using observations of such compact objects to probe some of the most intriguing general relativistic predictions in the strong-field regime: the absence of stable circular orbits near a compact object and the presence of event horizons around black-hole singularities. I discuss the need for a theoretical framework, within which future experiments will provide detailed, quantitative tests of gravity theories. Finally, I summarize the constraints imposed by current observations of neutron stars on potential deviations from general relativity.
9
2008-07-01
2008-11-18
11
Neutron stars, Black holes, Tests of relativistic gravity
publication
futamase.toshifumi
General relativity, Observational cosmology, General relativistic cosmology, Gravitational radiation
Astronomical Institute, Tohoku University, Sendai 980-8578, Japan
Toshifumi Futamase
author
Futamase
Toshifumi
de-rham.claudia
I am a cosmologist working on very early Universe Cosmology and Dark energy. More precisely, my main research interests cover Dark Energy and the CC Problem, SLED, Modified / Massive Gravity, EFT of codimension-2 objects, and Cosmological Perturbations.
CERCA & Physics Department, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
Claudia de Rham
author
de Rham
Claudia
lrr-2010-4-turyshev.slava
authorOrder
1
lrr-2003-1
Relativity in the Global Positioning System
2003LRR.....6....1A
The Global Positioning System (GPS) uses accurate, stable atomic clocks in satellites and on the ground to provide world-wide position and time determination. These clocks have gravitational and motional frequency shifts which are so large that, without carefully accounting for numerous relativistic effects, the system would not work. This paper discusses the conceptual basis, founded on special and general relativity, for navigation using GPS. Relativistic principles and effects which must be considered include the constancy of the speed of light, the equivalence principle, the Sagnac effect, time dilation, gravitational frequency shifts, and relativity of synchronization. Experimental tests of relativity obtained with a GPS receiver aboard the TOPEX/POSEIDON satellite will be discussed. Recently frequency jumps arising from satellite orbit adjustments have been identified as relativistic effects. These will be explained and some interesting applications of GPS will be discussed.
1
2003-01-08
2003-01-28
6
publication
lrr-2005-9
Spinning Strings and Integrable Spin Chains in the AdS/CFT Correspondence
2005-11-03
2005LRR.....8....9P
In this introductory review we discuss dynamical tests of the AdS_5 × S^5 string/N = 4 Super Yang-Mills duality. After a brief introduction to AdS/CFT, we argue that semiclassical string energies yield information on the quantum spectrum of the string in the limit of large angular momenta on the S^5. The energies of the folded and circular spinning string solutions rotating on a S^3 within the S^5 are derived, which yield all-loop predictions for the dual gauge theory scaling dimensions. These follow from the eigenvalues of the dilatation operator of N = 4 Super Yang-Mills in a minimal SU(2) subsector, and we display its reformulation in terms of a Heisenberg s = 1/2 spin chain along with the coordinate Bethe ansatz for its explicit diagonalization. In order to make contact to the spinning string energies, we then study the thermodynamic limit of the one-loop gauge theory Bethe equations and demonstrate the matching with the folded and closed string result at this loop order. Finally, the known gauge theory results at higher-loop orders are reviewed and the associated long-range spin chain Bethe ansatz is introduced, leading to an asymptotic all-loop conjecture for the gauge theory Bethe equations. This uncovers discrepancies at the three-loop order between gauge theory scaling dimensions and string theory energies, and the implications of this are discussed. Along the way, we comment on further developments and generalizations of the subject and point to the relevant literature.
9
2005-10-20
2005-11-30
8
String Theory, Supersymmetric Yang-Mills, AdS/CFT Correspondence
publication
chrusciel
University of Vienna, Austria
Piotr T. Chruściel
ebMember
chrusciel
Chruściel
Piotr T.
winicour.jeffrey
Theoretical General Relativity
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, 14476 Potsdam-Golm, Germany and Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, U.S.A.
800
Jeffrey Winicour
author
Winicour
Jeffrey
lrr-2009-1
Spectral Methods for Numerical Relativity
2008-10-20
2009LRR....12....1G
Equations arising in general relativity are usually too complicated to be solved analytically and one must rely on numerical methods to solve sets of coupled partial differential equations. Among the possible choices, this paper focuses on a class called spectral methods in which, typically, the various functions are expanded in sets of orthogonal polynomials or functions. First, a theoretical introduction of spectral expansion is given with a particular emphasis on the fast convergence of the spectral approximation. We then present different approaches to solving partial differential equations, first limiting ourselves to the one-dimensional case, with one or more domains. Generalization to more dimensions is then discussed. In particular, the case of time evolutions is carefully studied and the stability of such evolutions investigated. We then present results obtained by various groups in the field of general relativity by means of spectral methods. Work, which does not involve explicit time-evolutions, is discussed, going from rapidly-rotating strange stars to the computation of black-hole–binary initial data. Finally, the evolution of various systems of astrophysical interest are presented, from supernovae core collapse to black-hole–binary mergers.
1
2008-10-23
2009-01-09
12
Numerical methods
Numerical relativity
publication
beig
University of Vienna, Austria
Robert Beig
ebMember
beig
Beig
Robert
iyer
International Centre for Theoretical Sciences, TIFR, India
Bala R. Iyer
ebMember
iyer
Iyer
Bala R.
fragile.chris
I have a broad interest in computational astrophysics, particularly numerical simulations of novel hydrodynamic, magnetohydrodynamic (MHD), and radiation MHD effects in astrophysics. Currently, my primary interest is in developing and utilizing codes to study black hole accretion and the feedback of black holes on their environments through jets. This research may be applicable to quasars, active galactic nuclei (AGN), X-ray binaries, core-collapse supernovas, and gamma-ray bursts (GRBs), all of which contain jet-like features and are likely powered by accreting black holes.
Department of Physics & Astronomy, College of Charleston, Charleston, SC 29424, USA
P. Chris Fragile
author
Fragile
P. Chris
lrr-2004-3
Stochastic Gravity: Theory and Applications
2004LRR.....7....3H
Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued) stress-energy bi-tensor which describes the fluctuations of quantum matter fields in curved spacetimes. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to their correlation functions. The functional approach uses the Feynman-Vernon influence functional and the Schwinger-Keldysh closed-time-path effective action methods which are convenient for computations. It also brings out the open systems concepts and the statistical and stochastic contents of the theory such as dissipation, fluctuations, noise, and decoherence. We then focus on the properties of the stress-energy bi-tensor. We obtain a general expression for the noise kernel of a quantum field defined at two distinct points in an arbitrary curved spacetime as products of covariant derivatives of the quantum field's Green function. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime. We offer an analytical solution of the Einstein-Langevin equation and compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole (enclosed in a box). We derive a fluctuation-dissipation relation between the fluctuations in the radiation and the dissipative dynamics of metric fluctuations.
3
2004-02-27
2004-03-11
7
stochastic gravity
inflation
quantum fields in curved space
quantum gravity
semiclassical gravity
black holes
publication
lrr-2003-3
Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on the equilibrium properties and on the nonaxisymmetric instabilities in f-modes and r-modes have been updated and several new sections have been added on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity.
Rotating Stars in Relativity
2003LRR.....6....3S
3
2003-03-07
2003-06-16
Article revision. New section (4) and various subsections (2.3 - 2.5, 2.7.5 - 2.7.7, 2.8, 2.10) have been added. The number of references (342) has more than doubled.
6
relativistic stars
numerical relativity
oscillations
rotation
stability
publication
lrr-2012-7-heusler.markus
authorOrder
3
lrr-2002-6
This article is a guide to theorems on existence and global dynamics of solutions ofthe Einstein equations. It draws attention to open questions in the field. The local-in-time Cauchy problem, which is relatively well understood, is surveyed. Global results for solutions with various types of symmetry are discussed. A selection of results from Newtonian theory and special relativity that offer useful comparisons is presented. Treatments of global results in the case of small data and results on constructing spacetimes with prescribed singularity structure are given. A conjectural picture of the asymptotic behaviour of general cosmological solutions of the Einstein equations is built up. Some miscellaneous topics connected with the main theme are collected in a separate section.
Theorems on Existence and Global Dynamics for the Einstein Equations
2002LRR.....5....6R
6
2002-07-02
2002-09-27
Article revision. New sections (7 and 8) and subsections (2.4, 4.3 and 5.4) have been added, almost all sections have been updated. The number of references grew again considerably
5
publication
lrr-2012-6
Dynamical Boson Stars
2012-02-02
2012LRR....15....6L
The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called geons, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name boson stars. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.
6
2012-03-29
2012-05-08
15
Numerical relativity
Boson stars
publication
lrr-2008-8
We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of $1.5\,M_{\odot}$, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e=0.44) orbit around an unevolved companion.
Binary and Millisecond Pulsars
2008LRR....11....8L
8
2008-10-14
2008-09-19
2008-11-04
Significantly updated and revised 2005 version. Sections 2 and 4 have been extended by new subsections. 59 references have been added.
11
pulsars
publication
lrr-1998-9
Computational Cosmology: from the Early Universe to the Large Scale Structure
1
In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark--hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on thosecalculations designed to test different models of cosmology against the observed Universe.
9
1998-08-11
1998-09-15
Article revision that included addition of new figures, expanded existing sections, added several new sections
publication
2005-02-04
lrr-2005-3
Gravitational-Wave Data Analysis. Formalism and Sample Applications: The Gaussian Case
2005LRR.....8....3J
The article reviews the statistical theory of signal detection in application to analysis of deterministic gravitational-wave signals in the noise of a detector. Statistical foundations for the theory of signal detection and parameter estimation are presented. Several tools needed for both theoretical evaluation of the optimal data analysis methods and for their practical implementation are introduced. They include optimal signal-to-noise ratio, Fisher matrix, false alarm and detection probabilities, F-statistic, template placement, and fitting factor. These tools apply to the case of signals buried in a stationary and Gaussian noise. Algorithms to efficiently implement the optimal data analysis techniques are discussed. Formulas are given for a general gravitational-wave signal that includes as special cases most of the deterministic signals of interest.
3
2005-03-03
2005-03-21
8
gravitational waves, signal detection, parameter estimation
publication
lrr-2007-1
Relativistic Fluid Dynamics: Physics for Many Different Scales
2006-12-01
2007LRR....10....1A
The relativistic fluid is a highly successful model used to describe the dynamics of many-particle, relativistic systems. It takes as input basic physics from microscopic scales and yields as output predictions of bulk, macroscopic motion. By inverting the process, an understanding of bulk features can lead to insight into physics on the microscopic scale. Relativistic fluids have been used to model systems as ``small'' as heavy ions in collisions, and as large as the Universe itself, with ``intermediate'' sized objects like neutron stars being considered along the way. The purpose of this review is to discuss the mathematical and theoretical physics underpinnings of the relativistic (multiple) fluid model. We focus on the variational principle approach championed by Brandon Carter and his collaborators, in which a crucial element is to distinguish the momenta that are conjugate to the particle number density currents. This approach differs from the ``standard'' text-book derivation of the equations of motion from the divergence of the stress-energy tensor in that one explicitly obtains the relativistic Euler equation as an ``integrability'' condition on the relativistic vorticity. We discuss the conservation laws and the equations of motion in detail, and provide a number of (in our opinion) interesting and relevant applications of the general theory.
1
2007-01-12
2007-01-30
10
fluid dynamics, relativistic hydrodynamics, relativistic astrophysics, variational methods, classical field theory
publication
lucietti.james
My current research interests concern higher dimensional gravity/General Relativity, usually in the context of string theory and the gauge/gravity correspondence.
School of Mathematics and Maxwell Institute of Mathematical Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3JZ, UK
James Lucietti
author
Lucietti
James
lrr-2012-7
The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.
Stationary Black Holes: Uniqueness and Beyond
2012LRR....15....7C
7
2012-03-29
2011-08-23
2012-05-29
Major update of the original version by Markus Heusler from 1998. Piotr T. Chruściel and João Lopes Costa succeeded to this review's authorship. Significantly restructured and updated all sections; changes are too numerous to be usefully described here. The number of references increased from 186 to 329.
15
self-gravitating classical fields
uniqueness theorems
black holes
publication
downing.jonathan
Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, D-69120 Heidelberg, Germany
Jonathan M. B. Downing
author
Downing
Jonathan M. B.
lrr-2010-4-toth.viktor
authorOrder
2
lrr-2001-2
In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations (and numerical methods) applied to specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.
Computational Cosmology: From the Early Universe to the Large Scale Structure
2001LRR.....4....2A
2
2001-02-15
2001-03-20
Article revision adding two new sections on 'chaotic scalar field dynamics' and 'SZ effect' and an appendix on basic equations and numerical methods.
4
relativistic cosmology
numerical methods
physical cosmology
publication
lrr-2002-2-u1
Section 5.3.3: Correction of typographical error.
2003-12-05
update
benacquista.matthew
My research interest is in relativistic astrophysics and mathematical physics. Currently, I am studying a variety of binary systems as sources for the space-based gravitational wave detector (LISA). In particular, I am looking at globular cluster populations of relativistic binaries, gravitationally lensed quasars, and supermassive black hole systems in the cores of galaxies. I also hope to begin studying isolated neutron stars as possible sources for ground based gravitational wave interferometers such as LIGO or Virgo. I am the chair of the Task Force on Galactic Binary Populations as part of Working Group 1 of the LISA International Science Team.
Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX, U.S.A.
911
Matthew J. Benacquista
author
Benacquista
Matthew J.
berger.beverly
My research interests include numerical simulations of mathematical cosmologies to study both the nature of generic collapse and the nature of generic expansion. I am especially interested in the use of simulations to test mathematical conjectures and to explore those properties of solutions to Einstein's equations that might be amenable to mathematical analysis.
Physics Department, Oakland University, Rochester, MI 48309, U.S.A. and Physics Division, National Science Foundation, 4201 Wilson Blvd., Arlington, VA 22230 U.S.A.
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Beverly K. Berger
author
Berger
Beverly K.
pullin
Louisiana State University, USA
Jorge Pullin
ebMember
pullin
Pullin
Jorge
lrr-2014-5
On the History of Unified Field Theories. Part II. (ca. 1930 – ca. 1965)
2014-01-14
2014LRR....17....5G
The present review intends to provide an overall picture of the research concerning classical unified field theory, worldwide, in the decades between the mid-1930 and mid-1960. Main themes are the conceptual and methodical development of the field, the interaction among the scientists working in it, their opinions and interpretations. Next to the most prominent players, A. Einstein and E. Schrödinger, V. Hlavatý and the French groups around A. Lichnerowicz, M.-A. Tonnelat, and Y. Thiry are presented. It is shown that they have given contributions of comparable importance. The review also includes a few sections on the fringes of the central topic like Born–Infeld electromagnetic theory or scalar-tensor theory. Some comments on the structure and organization of research-groups are also made.
5
2014-05-13
2014-06-23
17
Differential geometry
History of science
Unified field theory
publication
lrr-2009-4-u1
Recent developments of the field are included. A few subsections and more than fifty new references are added, minor improvements and corrections of the text are made at several points, and the bibliography is updated.
2012-12-03
2012-12-07
update
lrr-2012-7-chruscielpiotr
authorOrder
1
faber.joshua
His work has focused on both binary neutron stars as well as black hole-neutron star binaries, evolved in post-Newtonian, conformally flat, and fully general relativistic gravitational formalisms. Most recently, he was part of a team responsible for fully general relativistic calculations of merging BH-NS binaries, studies of magnetohydrodynamic flows in the presence of puncture BHs, and the construction of highly accurate BH-NS initial data for use in dynamical simulations.
Center for Computational Relativity and Gravitation and School of Mathematical Sciences, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester NY 14623, USA
Joshua A. Faber
author
Faber
Joshua A.
goenner.hubert
Relativistic theories of gravitation, in particular scalar-tensor theories and, recently, a Finsler generalization of flat space-time; relativistic thermodynamics; exact solutions of Einstein's equations and their symmetries; cosmology (but no speculations on early universe!); history of special and general relativity and its creator Einstein; science research.
University of Göttingen, Institut für Theoretische Physik, Tammannstr. 1, D-37077 Göttingen, Germany
665
Hubert F. M. Goenner
author
Goenner
Hubert F. M.
lrr-2011-4
The main purpose of this article is to provide a guide to theorems on global properties of solutions to the Einstein-Vlasov system. This system couples Einstein’s equations to a kinetic matter model. Kinetic theory has been an important field of research during several decades in which the main focus has been on non-relativistic and special relativistic physics, i.e., to model the dynamics of neutral gases, plasmas, and Newtonian self-gravitating systems. In 1990, Rendall and Rein initiated a mathematical study of the Einstein-Vlasov system. Since then many theorems on global properties of solutions to this system have been established. This paper gives introductions to kinetic theory in non-curved spacetimes and then the Einstein–Vlasov system is introduced. We believe that a good understanding of kinetic theory in non-curved spacetimes is fundamental to a good comprehension of kinetic theory in general relativity.
The Einstein-Vlasov System/Kinetic Theory
2011LRR....14....4A
4
2011-05-06
2011-02-24
2011-05-27
This is a revised and updated version of the article from 2005. A number of new sections on the Einstein-Vlasov system have been added, e.g., on the formation of black holes and trapped surfaces, on self-similar solutions, on the structure of static solutions, on Buchdahl type inequalities, on the stability of cosmological solutions, and on axisymmetric solutions. Some of the previous sections have been significantly extended. The number of references has increased from 121 to 197.
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Einstein-Vlasov system
Global existence
Vlasov-Poisson system
Nordström-Vlasov system
Kinetic theory
publication
comer.greg
A key question is the role of multiple fluid dynamics on the creation and emission of gravitational waves from neutron stars. Is such dynamics detectable by, say, future versions of LIGO?
Department of Physics & Center for Fluids at All Scales, Saint Louis University, St. Louis, MO, 63156-0907, U.S.A.
Gregory L. Comer
author
Comer
Gregory L.
lrr-2007-5
As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term “critical phenomena”. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. Critical phenomena give a natural route from smooth initial data to arbitrarily large curvatures visible from infinity, and are therefore likely to be relevant for cosmic censorship, quantum gravity, astrophysics, and our general understanding of the dynamics of general relativity.
Critical Phenomena in Gravitational Collapse
2007LRR....10....5G
5
2007-12-06
2007-11-28
2007-12-11
Completely restructured and updated review with new co-author José M. Martín-García. Omitted some details not central to the topic, e.g., in Sections 3.2 and 4.1 (new 2.4) of 1999 version; original Section 4.4 with technical details has been dropped. References have been updated and increased in number from 124 to 195.
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Black holes
Scaling laws
Numerical relativity
Naked singularities
Gravitational collapse
Stability
Phase space
Critical phenomena
Self-similarity
publication