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 $\beta_{PBH}$. 
Edgar Bugaev, Peter Klimai
astro-ph.CO hep-ph