Gravitational waves from first-order phase transitions in LISA: reconstruction pipeline and physics interpretation

TL;DR

This paper develops a reconstruction pipeline for gravitational wave signals from first-order phase transitions for LISA, enabling parameter estimation and physics interpretation beyond the Standard Model.

Contribution

It introduces a template databank and forecasting tools for analyzing stochastic gravitational wave backgrounds from cosmological phase transitions with LISA.

Findings

LISA can reconstruct phase transition parameters with better than 10% accuracy under certain conditions.

The pipeline accounts for foregrounds and sources, improving signal detection.

Reconstructed parameters can be mapped to models beyond the Standard Model.

Abstract

We develop a tool for the analysis of stochastic gravitational wave backgrounds from cosmological first-order phase transitions with LISA: we initiate a template databank for these signals, prototype their searches, and forecast their reconstruction. The templates encompass the gravitational wave signals sourced by bubble collisions, sound waves and turbulence. Accounting for Galactic and extra-Galactic foregrounds, we forecast the region of the parameter space that LISA will reconstruct with better than $\sim 10\,\%$ accuracy, if certain experimental and theoretical uncertainties are solved by the time LISA flies. We illustrate the accuracy with which LISA can reconstruct the parameters on a few benchmark signals, both in terms of the template parameters and the phase transition ones. To show the impact of the forecasts on physics beyond the Standard Model, we map the reconstructed benchmark measurements into the parameter spaces of the singlet extension of the Standard Model and of the classically conformal invariant $U(1)_{B-L}$ model.