Revealing the Cosmic History with Gravitational Waves

TL;DR

This paper discusses how measuring the stochastic gravitational wave background can uncover detailed cosmic history, including inflation, reheating, and the early hot big bang, using a well-motivated particle physics model.

Contribution

It demonstrates the potential of gravitational wave measurements to reveal the universe's inflationary and post-inflationary history within a comprehensive Standard Model extension.

Findings

Gravitational wave background encodes information about inflation and reheating.

A specific Standard Model extension predicts detectable gravitational wave signatures.

Measurement can distinguish different phases of early universe evolution.

Abstract

The characteristics of the cosmic microwave background provide circumstantial evidence that the hot radiation-dominated epoch in the early universe was preceded by a period of inflationary expansion. Here, we show how a measurement of the stochastic gravitational wave background can reveal the cosmic history and the physical conditions during inflation, subsequent pre- and re-heating, and the beginning of the hot big bang era. This is exemplified with a particularly well-motivated and predictive minimal extension of the Standard Model which is known to provide a complete model for particle physics -- up to the Planck scale, and for cosmology -- back to inflation.