The Gravitational Afterglow of Boson Stars

TL;DR

This paper investigates the long-lasting gravitational wave signals following boson-star mergers, using advanced numerical relativity techniques to identify unique signatures that could help distinguish these events from other sources.

Contribution

The study introduces improved initial data methods and a new angular momentum measure, enabling detailed simulation of the extended gravitational wave afterglow from boson-star mergers.

Findings

The gravitational afterglow lasts much longer than the spin-down timescale.

The afterglow has a characteristic signal distinct from other astrophysical sources.

Simulations show prolonged gravitational wave emission post-merger.

Abstract

In this work we study the long-lived post-merger gravitational wave signature of a boson-star binary coalescence. We use full numerical relativity to simulate the post-merger and track the gravitational afterglow over an extended period of time. We implement recent innovations for the binary initial data, which significantly reduce spurious initial excitations of the scalar field profiles, as well as a measure for the angular momentum that allows us to track the total momentum of the spatial volume, including the curvature contribution. Crucially, we find the afterglow to last much longer than the spin-down timescale. This prolonged gravitational wave afterglow provides a characteristic signal that may distinguish it from other astrophysical sources.