Speaker
Description
Assuming spherical symmetry we consider primordial black hole formation from the collapse of adiabatic cosmological perturbations of a massless scalar field, sourced by a time independent curvature profile $\mathcal{R}(r)$ imposed on super horizon scale. We have proved that a massless scalar field is equivalent to a perfect fluid where the pressure is equal to the total energy density (i.e. $p=\rho$ equation of state ). Using the comoving and the constant mean curvature gauge we build up a numerical code based on the BSSN conformal decomposition, developed specifically for this problem, computing the threshold $\delta_c$ for different initial configurations. This will allow to compute the abundance and mass distribution of PBHs formed when the early Universe is dominated by massless scalar field.
