COSMOLOGICAL PARAMETERS FROM THE MICROWAVE BACKGROUND AND LARGE-SCALE STRUCTURE

A brief overview is given of the mechanisms that generate CMB anisotropies, concentrating on the model degeneracies intrinsic to CMB data alone. These degeneracies are broken by the addition of LSS information, resulting in a well-specified model. Spatial curvature must be low, with |Ω – 1| < 0.05 at 95% confidence. If the universe is exactly flat, the CMB power spectrum measures the combination Ω_mh³ = 0.092 ± 6%. Adding LSS data also breaks this degeneracy, requiring Ω_m = 0.26 ± 15% and h = 0.71 ± 6%. The preferred model is scalar-dominated, although a substantial tensor contribution is hard to rule out without a precise measurement of the amplitude of mass fluctuations. The prospects for further tests and refinements of this picture are discussed.