General Properties of the Gravitational Wave Spectrum from Phase Transitions

TL;DR

This paper explores the fundamental characteristics of gravitational wave spectra generated by early universe phase transitions, focusing on their shape, peak frequency, and the impact of bubble collisions, providing a comparative analysis of recent models.

Contribution

It offers a general framework for understanding gravitational wave spectra from phase transitions and compares various recent results on bubble collision models.

Findings

The spectrum shape and peak frequency depend on phase transition physics.

Different bubble collision models yield varying gravitational wave predictions.

The paper clarifies the key factors influencing gravitational wave signals from early universe events.

Abstract

In this paper we discuss some general aspects of the gravitational wave background arising from post-inflationary short-lasting cosmological events such as phase transitions. We concentrate on the physics which determines the shape and the peak frequency of the gravitational wave spectrum. We then apply our general findings to the case of bubble collisions during a first order phase transition and compare different results in the recent literature.