MICROWAVE BACKGROUND ANISOTROPIES IN PRIMEVAL ISOCURVATURE BARYON MODELS - CONSTRAINTS ON THE COSMOLOGICAL PARAMETERS

We have performed the most comprehensive predictions of the temperature fluctuations deltaT/T in the primeval isocurvature baryon models assuming that the universe never recombined to see whether or not the models are consistent with the recent data on the cosmic microwave background anisotropies. More specifically, we computed the deltaT/T corresponding to the experimental set-up by the South-Pole and the Ownes Valley experiments as well as the COBE satellite. The amplitudes of the predicted deltaT/T are normalized by means of the COBE 10-degrees data. The resulting constraints on the models are presented on n - OMEGA(b), plane in the case of lambda0 = 1 - OMEGA(b) (flat models) and lambda0 = 0 (open models), where n is the primordial spectral index of entropy fluctuations and OMEGA(b) is the present baryon density parameter. Our results imply that the primordial isocurvature baryon models cannot be reconciled with the current observations for any reasonable set of cosmological parameters, if the universe never recombined.