Inflationary Gravitational Waves and the Evolution of the Early Universe

TL;DR

This paper investigates how early universe phenomena like phase transitions and dark radiation influence inflationary gravitational wave spectra, offering potential probes into high-energy physics and cosmic history.

Contribution

It introduces a comprehensive analysis of various early universe events and their signatures in gravitational wave spectra, enhancing understanding of high-energy physics.

Findings

Early universe phenomena imprint distinct features on gravitational wave spectra.

Gravitational wave signatures can reveal details about phase transitions and dark radiation.

Potential for gravitational wave observations to inform high-energy physics models.

Abstract

We study the effects of various phenomena which may have happened in the early universe on the spectrum of inflationary gravitational waves. The phenomena include phase transitions, entropy productions from non-relativistic matter, the production of dark radiation, and decoupling of dark matter/radiation from thermal bath. These events can create several characteristic signatures in the inflationary gravitational wave spectrum, which may be direct probes of the history of the early universe and the nature of high-energy physics.