BLUE SPECTRA AND INDUCED FORMATION OF PRIMORDIAL BLACK-HOLES - ART. NO. 103517

We investigate the statistical properties of primordial black hole (PB H) formation in the very early Universe. We show that the high level o f inhomogeneity of the early Universe leads to the formation of the fi rst generation PBHs. This causes later the appearance of a dustlike ph ase of the cosmological expansion. We discuss here a new mechanism for the second generation of PBH formation during the dustlike phase. Thi s mechanism is based on the coagulation process. We demonstrate that t he blue power spectrum of initial adiabatic perturbations after inflat ion leads to overproduction of primordial black holes with 10(9) g les s than or equal to M less than or equal to 10(15) g if the power index is n greater than or equal to 1.2. [S0556-2821(98)10620-3].