A MODIFICATION OF THE BARYONIC DARK-MATTER MODEL

The conventional baryonic dark matter model of galaxy formation uses t he concept of entropy fluctuations. The key idea of this picture is ba sed on the assumption that already before the recombination on the sca les characterized by masses not bigger than similar to 10(9) M-. the e ntropic fluctuations were non linear, and they were formed by non-grav itational processes. In this paper the basis of a modification of the baryonic dark matter picture is presented. This modification uses - in stead of the entropic fluctuations - the concept of adiabatic perturba tions existing only during and after the recombination. It reproduces the key idea of conventional picture: roughly for solar masses bold an isotropies should occur immediately during the recombination. Neverthe less, contrary to the conventinonal picture, this occurs without any n on-gravitational phenomenons. All this follows from the so called ''Be ssel-Macdonald'' instability, which is predicted to exist by a careful mathematical analysis of the key equation of adiabatic perturbations.