Hydrodynamics of primary black hole formation and the dependence of the process on the equation of state

The dependence of the primary black hole (PBN) process and subsequent gas accretion on the equation of state is investigated. The problem of solved numerically assuming the spherical symmetry of the process. The principal quantitative characteristics of the PBH formation process for seven values of the parameter γ in the equation of state P = (γ-1)epsilon, where P and epsilon stand for the pressure and energy density. For three cases: 1) the ultrarelativistic gas, 2) the equation of state softer than the for the relativistic gas, 3) the hardest possible equation of state the RBH formation process for equations of state is presented in graphical form. The time dependence of the PBH mass is given. It is shown that the harder is the equation of state the more difficult is the PBH formation