Particle Physics and Cosmology

Observational tests of cosmological theories are reviewed, with emphasis on the cosmological microwave background (CMB) radiation and dark matter. Present observations of the CMB are consistent with inflationary models, that have already excluded some alternatives. Particle dark matter candidates are reviewed, including massive neutrinos, the lightest supersymmetric particle (LSP), ultra-heavy relics from the big bang, and cosmological vacuum energy. Finally, some personal guesses at confidence ratings are hazarded. (71 refs).