Gravitational waves from cosmological first order phase transitions

TL;DR

This paper investigates how first order phase transitions in the early Universe produce gravitational waves, highlighting that sound waves are the main source and can lead to stronger signals than previously thought.

Contribution

The study uses large-scale simulations to show that sound waves dominate gravitational wave production during cosmological phase transitions, revealing stronger signals than earlier estimates.

Findings

Sound waves are the primary source of gravitational waves.

Gravitational wave signals are stronger than previous predictions.

Large-scale simulations provide new insights into early Universe phenomena.

Abstract

First order phase transitions in the early Universe generate gravitational waves, which may be observable in future space-based gravitational wave observatiories, e.g. the European eLISA satellite constellation. The gravitational waves provide an unprecedented direct view of the Universe at the time of their creation. We study the generation of the gravitational waves during a first order phase transition using large-scale simulations of a model consisting of relativistic fluid and an order parameter field. We observe that the dominant source of gravitational waves is the sound generated by the transition, resulting in considerably stronger radiation than earlier calculations have indicated.