Primordial black holes from local features of the inflaton potential

TL;DR

This paper investigates how local features in the inflaton potential during single field inflation can enhance curvature perturbations, leading to primordial black hole formation across various mass ranges, including asteroid masses.

Contribution

It introduces a mechanism where local features in the inflaton potential amplify curvature perturbations, enabling PBH production in different mass ranges with observationally consistent abundances.

Findings

Features can significantly increase PBH abundance.

Models can produce PBHs in asteroid mass range.

Parameter tuning allows compatibility with observational constraints.

Abstract

Primordial black holes (PBH) can form in the early Universe from peaks of the primordial curvature perturbations. The statistics of the peaks determines the abundance of PBHs, and is related to the amplitude of the primordial curvature spectrum. We study single field inflationary models with local features of the inflaton potential which induce a growth of curvature perturbations on super-horizon scales, which can increase the spectrum, and consequently the predicted PBHs abundance. We compute the effects of the different parameters of the features on the PBHs abundance, giving some example of models compatible with observational constraints. The mechanism is general, and can induce the PBH production in diffent mass ranges by appropriately tuning the parameters, and we give a specific example producing PBHs with abundance compatible with asteroid mass constraints.