Journal of Physical Studies 5(2), 177–215 (2001) DOI: https://doi.org/10.30970/jps.05.177 THE THEORY OF CMB ANISOTROPIES R. Durrer Université de Genève, Département de Physique Théorique, Quai E. Ansermet 24, 1211 Genève 4, Switzerland; and School of Natural Sciences, Institute for Advanced Study Einstein Drive, Princeton, NJ 08540, USA

This is a review of the theory of cosmic microwave background (CMB) anisotropies. It is an updated version of a course given in spring 1999 at the `troisieme cycle de la Suisse Romande'. An introduction to gauge invariant cosmological perturbation theory is given and CMB anisotropies are treated in this context. Simple analytical approximations for the acoustic peak positions for adiabatic and isocurvature perturbations are derived. Silk damping is discussed by an analytic approximation. A short description of the present status of observations and parameter estimation followed by a critical discussion terminated the review. The full system of differential equations for CMB anisotropies and polarization needed in a numerical treatment is also developed and given in an appendix.

PACS number(s): 98.80 98.80.Es 98.80.Hw 98.80.Cq

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