Go to previous page Go up Go to next page

3.9 3D Einstein-Klein-Gordon system

The Einstein-Klein-Gordon (EKG) system can be used to simulate many interesting physical phenomena. In 1D, characteristic EKG codes have been used to simulate critical phenomena and the perturbation of black holes (see Section 3.1), and a Cauchy EKG code has been used to study boson star dynamics [188]. (The characteristic approach has not yet been applied to the problem of stable 1D boson stars.) Extending these codes to 3D would open up a new range of possibilities, e.g., the possibility to study radiation from a boson star orbiting a black hole. A first step in that direction has been achieved with the construction of a 3D characteristic code by incorporating a massless scalar field into the PITT code [16]. Since the scalar and gravitational evolution equations have the same basic form, the same evolution algorithm could be utilized. The code was tested to be second order convergent and stable. It was applied to the fully nonlinear simulation of an asymmetric pulse of ingoing scalar radiation propagating toward a Schwarzschild black hole. The resulting scalar radiation and gravitational news backscattered to + I was computed. The amplitudes of the scalar and gravitational radiation modes exhibited the expected power law scaling with respect to the initial pulse amplitude. In addition, the computed ringdown frequencies agreed with the results from perturbative quasinormal mode calculations.


  Go to previous page Go up Go to next page