Primordial black holes and secondary gravitational waves from chaotic inflation

TL;DR

This paper modifies chaotic inflation with a peak function in the kinetic term to satisfy observational constraints and generate primordial black holes and secondary gravitational waves, with minimal impact from non-Gaussianities.

Contribution

It introduces a novel enhancement mechanism in noncanonical kinetic terms that enables chaotic inflation to produce observable primordial black holes and gravitational waves.

Findings

Chaotic inflation model with peak function satisfies observational constraints.

Enhanced scalar power spectrum by seven orders of magnitude at small scales.

Primordial black holes and secondary gravitational waves are produced with varying masses and frequencies.

Abstract

Chaotic inflation is inconsistent with the observational constraint at 68\% CL. Here, we show that the enhancement mechanism with a peak function in the noncanonical kinetic term not only helps the chaotic model $V(\phi)=V_0\phi^{1/3}$ satisfy the observational constraint at large scales but also enhances the primordial scalar power spectrum by seven orders of magnitude at small scales. The enhanced curvature perturbations can produce primordial black holes of different masses and secondary gravitational waves with different peak frequencies. We also show that the non-Gaussianities of curvature perturbations have little effect on the abundance of primordial black holes and energy density of the scalar-induced secondary gravitational waves.