Primordial black holes and inflation from double-well potentials

TL;DR

This paper explores how double-well inflationary potentials can produce large peaks in the curvature power spectrum, potentially leading to primordial black hole formation, with models fitting current CMB data and requiring less fine-tuning.

Contribution

It introduces a new class of inflationary models with double-well potentials that generate prominent power spectrum peaks suitable for primordial black hole formation, with improved parameter robustness.

Findings

Double-well potentials produce more pronounced power spectrum peaks.

Models are consistent with latest CMB observations.

Potential to generate large curvature perturbations for primordial black holes.

Abstract

We investigate the formation of large peaks in the inflationary curvature power spectrum from double-well potentials. In such scenarios, the initial CMB spectrum is created at large field values. Subsequently, the inflaton will cross one of the minima and will decelerate rapidly as it reaches the local maximum at the origin, either falling back or crossing it. During this final phase, a significant peak in the curvature power spectrum can be generated. Our analysis reveals that this class of models produces more pronounced peaks than the more commonly studied quasi-inflection point scenarios with less tuning for the model parameters. Finally, we construct an explicit theoretically motivated inflationary scenario that is consistent with the latest CMB observations and capable of generating sufficiently large curvature perturbations for primordial black holes.