Gravitational waves from first order phase transitions as a probe of an early matter domination era and its inverse problem

TL;DR

This paper explores how gravitational waves from early universe phase transitions can reveal details about the universe's thermal history, especially during matter domination, and discusses challenges in interpreting these signals.

Contribution

It introduces a method to extract properties of phase transitions from gravitational wave signals in a matter-dominated universe and addresses the inverse problem of parameter degeneracy.

Findings

Unique gravitational wave features from matter domination era.

Method to infer phase transition properties from GW signals.

Discussion on parameter degeneracy in inverse problem.

Abstract

We investigate the gravitational wave background from a first order phase transition in a matter-dominated universe, and show that it has a unique feature from which important information about the properties of the phase transition and thermal history of the universe can be easily extracted. Also, we discuss the inverse problem of such a gravitational wave background in view of the degeneracy among macroscopic parameters governing the signal.