Gravitational waves from cosmological first-order phase transitions with precise hydrodynamics

TL;DR

This paper presents a self-consistent numerical method to accurately calculate gravitational wave spectra from sound waves during cosmological phase transitions, improving upon previous models by deriving the equation of state from the effective potential.

Contribution

We develop a novel, adaptable computational approach that directly derives hydrodynamic quantities from the effective potential, enabling precise gravitational wave predictions for various particle physics models.

Findings

First self-consistent numerical calculation for the real singlet extension of the standard model.

Method reduces reliance on approximations like the bag model.

Provides a fast, reliable way to explore gravitational wave signals across models.

Abstract

We calculate the gravitational wave spectrum generated by sound waves during a cosmological phase transition, incorporating several advancements beyond the current state-of-the-art. Rather than relying on the bag model or similar approximations, we derive the equation of state directly from the effective potential. This approach enables us to accurately determine the hydrodynamic quantities, which serve as initial conditions in a generalised hybrid simulation. This simulation tracks the fluid evolution after bubble collisions, leading to the generation of gravitational waves. Our work is the first self-consistent numerical calculation of gravitational waves for the real singlet extension of the standard model. Our computational method is adaptable to any particle physics model, offering a fast and reliable way to calculate gravitational waves generated by sound waves. With fewer approximations, our approach provides a robust foundation for precise gravitational wave calculations and allows for the exploration of model-independent features of gravitational waves from phase transitions.