LIMITS ON COLD DARK MATTER COSMOLOGIES FROM NEW ANISOTROPY BOUNDS ON THE COSMIC MICROWAVE BACKGROUND

The recent UCSB South Pole experiment on the cosmic microwave background anisotropy imposes stringent constraints on cold dark matter cosmologies with variable baryonic and dark matter content. We have taken into account both the sampling strategy and the instrumental noise of the experiment by performing Monte Carlo simulations of the theoretically predicted microwave sky and have analyzed the experimental and simulated data using both the likelihood ratio test and a chi-2 analysis. The latter provides a slightly more stringent upper limit on the rms differential (single subtraction) temperature anisotropy: delta-T/T < 4.0 x 10(-5), on the angular scale probed by the UCSB South Pole experiment. This limit, in practice independent of the parameters of the CDM models considered, has a 95% confidence level and a power of the test beta = 55%. In addition we test Gaussian correlation function models and place a 95% confidence level, 41% power upper limit of T/T < 3.5 x 10 at an angular scale of 20"-30". We also set a lower limit (95% confidence level, beta = 55%) on the density parameter of cold dark matter universes with greater-than-or-similar-to 3% baryon abundance and a Hubble constant of 50 km s-1 Mpc-1: OMEGA-0 greater-than-or-similar-to 0.6b-1, where b is the bias factor (1 less-than-or-similar-to b less-than-or-similar-to 2), equal to unity only if light traces mass.