Primordial Black Holes from Inflation and non-Gaussianity

TL;DR

This paper presents an exact method to calculate the abundance of primordial black holes formed during inflation, emphasizing the significant impact of non-Gaussianities on their formation and distribution.

Contribution

It introduces a path-integral approach for precise mass fraction calculations considering non-Gaussianity, improving upon Gaussian-based estimates.

Findings

Non-Gaussianities significantly affect PBH abundance estimates.

Gaussian assumptions can lead to severe inaccuracies in PBH formation predictions.

Different inflation models show varying impacts of non-Gaussianity on PBH clustering.

Abstract

Primordial black holes may owe their origin to the small-scale enhancement of the comoving curvature perturbation generated during inflation. Their mass fraction at formation is markedly sensitive to possible non-Gaussianities in such large, but rare fluctuations. We discuss a path-integral formulation which provides the exact mass fraction of primordial black holes at formation in the presence of non-Gaussianity. Through a couple of classes of models, one based on single-field inflation and the other on spectator fields, we show that restricting to a Gaussian statistics may lead to severe inaccuracies in the estimate of the mass fraction as well as on the clustering properties of the primordial black holes.