Formation of primordial black holes from non-Gaussian perturbations produced in a waterfall transition

TL;DR

This paper investigates how non-Gaussian curvature perturbations generated during waterfall transitions at the end of hybrid inflation can lead to primordial black hole formation, providing constraints on inflationary models based on PBH abundance limits.

Contribution

It presents a detailed calculation of PBH abundances and mass spectra considering non-Gaussian perturbations from waterfall transitions, which is a novel approach in this context.

Findings

Derived PBH mass spectra for the model.

Established constraints on inflationary potential parameters.

Showed the impact of non-Gaussianity on PBH formation.

Abstract

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 $\beta_{PBH}$.