Extreme gravitational waves from inflaton fragmentation

TL;DR

This paper introduces a process in inflationary models with a complex inflaton field that generates a sharply peaked, ultra-high frequency gravitational wave spectrum, potentially detectable by future experiments.

Contribution

It identifies a generic mechanism in certain inflationary models that produces extreme, sharply peaked gravitational waves with high energy density and frequency.

Findings

Produces a sharply peaked gravitational wave spectrum

Energy density fraction reaches 10^-9

Frequency around 10^10 Hz

Abstract

Although inflationary models generically predict a flat spectrum of gravitational waves, we point out a general process that produces a sharply peaked spectrum of gravitational radiation. This process is generic for inflationary models with a complex inflaton field which couples to fermions. In particular, for chaotic models these may be the most extreme gravitational waves in the Universe with a very large energy density fraction 10^-9 and ultra-high frequency, 10^10 Hz. Although not amenable to space based interferometers, the signal from this model may be detectable by future table top experiments.