Gravitational and electromagnetic signatures of accretion into a charged black hole

TL;DR

This paper derives and solves coupled electromagnetic and gravitational perturbation equations in a charged black hole background, analyzing how infalling matter influences both gravitational and electromagnetic wave responses.

Contribution

It provides the first detailed numerical solutions to coupled perturbations with sources in a charged black hole, exploring the interplay between gravitational and electromagnetic signals.

Findings

Waveforms characterized for both signals

Dependence of wave responses on infalling matter parameters

Numerical solutions of coupled wave equations

Abstract

We present the derivation and the solutions to the coupled electromagnetic and gravitational perturbations with sources in a charged black hole background. We work in the so called ghost gauge and consider as source of the perturbations the infall of radial currents. In this way, we study a system in which it is provoked a response involving both, gravitational and electromagnetic waves, which allows us to analyze the dependence between them. We solve numerically the wave equations that describe both signals, characterize the waveforms and study the relation between the input parameters of the infalling matter with those of the gravitational and electromagnetic responses.