Gravitational waves from scalar field accretion

TL;DR

This paper investigates how scalar field halos interacting with Schwarzschild black holes can generate gravitational waves, potentially revealing information about the matter involved in such astrophysical processes.

Contribution

It provides a theoretical analysis of gravitational wave emission from scalar field accretion onto black holes using a simplified spherical model.

Findings

Gravitational waves depend on scalar field parameters

Waves carry information about the infalling matter

Simplified spherical harmonic approach used

Abstract

Our aim in this work is to outline some physical consequences of the interaction between black holes and scalar field halos in terms of gravitational waves. In doing so, the black hole is taken as a static and spherically symmetric gravitational source, {\it i. e.} the Schwarzschild black hole, and we work within the test field approximation, considering that the scalar field lives in the curved space-time outside the black hole. We focused on the emission of gravitational waves when the black hole is perturbed by the surrounding scalar field matter. The symmetries of the spacetime and the simplicity of the matter source allow, by means of a spherical harmonic decomposition, to study the problem by means of a one dimensional description. Some properties of such gravitational waves are discussed as a function of the parameters of the infalling scalar field, and allow us to make the conjecture that the gravitational waves carry information on the type of matter that generated them.