Generating Gravitational Waves After Inflation

TL;DR

This paper reviews two mechanisms for generating gravitational waves after inflation—preheating and Hawking radiation from primordial black holes—highlighting their potential to reveal end-of-inflation physics.

Contribution

It introduces and contrasts two post-inflation gravitational wave generation mechanisms, expanding understanding of signals from the inflationary epoch's end.

Findings

Preheating can produce detectable gravitational waves.

Primordial black hole decay emits gravitational waves via Hawking radiation.

These mechanisms offer insights into the physics of the inflationary end phase.

Abstract

I review two mechanisms by which gravitational waves can be generated at the end of inflation: preheating, and gravitons Hawking radiated during the decay of very small primordial black holes. These mechanisms are contrasted with the gravitational waves during inflation, and may provide a window into the physical processes that govern the end of the inflationary phase.