Generation of primordial black holes from an inflation model with modified dispersion relation

TL;DR

This paper investigates how a modified dispersion relation in a specific inflation model can enhance scalar perturbations, leading to primordial black hole formation and scalar-induced gravitational waves, offering insights into dark matter and astrophysical objects.

Contribution

It introduces the DINKIC inflation model with a modified dispersion relation and analyzes its effects on PBH production and gravitational wave formation.

Findings

Enhanced scalar power spectrum due to modified dispersion relation

Potential for significant primordial black hole abundance

Generation of scalar-induced gravitational waves

Abstract

A primordial black hole (PBH) is interesting to people for its ability of explaining dark matter as well as supermassive astrophysical objects. In the normal inflation scenario, the generation of PBHs usually requires an enhanced power spectrum of scalar perturbation at the end of inflation era, which is expected when the dispersion relation of the inflaton field gets modified. In this work, we study a kind of inflation model called {the \it Dirac-Born-Infeld-inspired nonminimal kinetic coupling (DINKIC)} model, where the dispersion relation is modified by a square root existing in the field Lagrangian. We discuss the enhancement of scalar power spectrum due to the modified dispersion relation, as well as the abundance of PBHs produced by the Press-Schechter collapse mechanism. We also discuss the formation of scalar-induced gravitational waves by linear scalar perturbations.