Identifying the most crucial parameters of the initial curvature profile
  for primordial black hole formation
  Primordial black holes (PBHs) are an important tool in cosmology to probe the
primordial spectrum of small-scale curvature perturbations that reenter the
cosmological horizon during radiation domination epoch. We numerically solve
the evolution of spherically symmetric highly perturbed configurations to
clarify the criteria of PBHs formation using an extremely wide class of
curvature profiles characterized by five parameters, (in contrast to only two
parameters used in all previous papers) which specify the curvature profiles
not only at the central region but also at the outer boundary of
configurations. It is shown that formation or non-formation of PBHs is
determined entirely by only two master parameters one of which can be presented
as an integral of curvature over initial configurations and the other is
presented in terms of the position of the boundary and the edge of the core.
