Formation of primordial black holes from non-Gaussian perturbations
  produced in a waterfall transition
  We consider the process of primordial black hole (PBH) formation originated
from primordial curvature perturbations produced during waterfall transition
(with tachyonic instability), at the end of hybrid inflation. It is known that
in such inflation models, rather large values of curvature perturbation
amplitudes can be reached, which can potentially cause a significant PBH
production in the early Universe. The probability distributions of density
perturbation amplitudes in this case can be strongly non-Gaussian, which
requires a special treatment. We calculated PBH abundances and PBH mass spectra
for the model, and analyzed their dependence on model parameters. We obtained
the constraints on the parameters of the inflationary potential, using the
available limits on $\beta_{PBH}$.
