Primordial black holes and gravitational waves from non-canonical inflation

TL;DR

This paper introduces a novel mechanism for primordial black hole formation during non-canonical inflation, linking it to potential dark matter candidates and detectable gravitational wave signals for future observatories.

Contribution

It proposes a new PBH production mechanism in non-canonical inflation with steep-deformed potentials, constrains non-canonical exponents, and predicts observable gravitational wave backgrounds.

Findings

Formation of asteroid-mass PBHs that could be dark matter

Production of solar-mass PBHs within LIGO/VIRGO band

Detectable stochastic gravitational-wave background predicted

Abstract

Primordial black holes (PBHs) can generically form in inflationary setups through the collapse of enhanced cosmological perturbations, providing us access to the early Universe through their associated observational signatures. In the current work we propose a new mechanism of PBH production within non-canonical inflation, using a class of steep-deformed inflationary potentials compatible with natural values for the non-canonical exponents. In particular, by requiring significant PBH production we extract constraints on the non-canonical exponents. Additionally, we find that our scenario can lead to the formation of asteroid-mass PBHs, which can account for the totality of the dark matter, as well as to production of solar-mass PBHs within the LIGO/VIRGO detection band. Finally, we find that the enhanced cosmological perturbations which collapse to form PBHs can produce a stochastic gravitational-wave (GW) background induced by second-order gravitational interactions. Very interestingly, we obtain a GW signal detectable by future GW experiments, in particular by SKA, LISA and BBO.