# The Cosmic Microwave Background

**A.W. Jones
**

Mullard Radio Astronomy Observatory, Cavendish Laboratory,

Madingley Road, Cambridge CB3 OHE, U.K.

**A.N. Lasenby
**

Mullard Radio Astronomy Observatory, Cavendish Laboratory,

Madingley Road, Cambridge CB3 OHE, U.K.

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Abstract

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 and
using the maximum likelihood technique. In addition, secondary anisotropies due to the
Sunyaev–Zel’dovich effect are described.