EARLY COSMIC FORMATION OF MASSIVE BLACK-HOLES

The evolution of nonlinear density fluctuations around the Jeans mass shortly after cosmological recombination is analyzed using a three-dimensional hydrodynamics/dark-matter code. The cosmic background radiation (CBR) exerts Compton friction on free electrons in resistance to their peculiar velocities. The baryonic dynamics therefore depends strongly on the gas ionization history. For a variety of scenarios for the local reionization and in systems with or without non-baryonic components, the baryons lose angular momentum efficiently and collapse to form a compact optically thick object which would probably quickly evolve into a massive black hole. Attention is concentrated on elucidating some of the novel physical effects in early cosmological collapses, but ways in which more realistic calculations might be made and in which the scenario could be incorporated into a more complete cosmogonic model are discussed.