Scattering on Quasi-Spherical Black-Holes: Features and Beyond

TL;DR

This paper investigates how gravitational waves scatter off distorted black holes in different spacetimes, revealing the influence of background geometry deformation on scattering properties and stability.

Contribution

It generalizes the Regge-Wheeler-Zerilli equations to include distorted black holes in Minkowski and Anti-de Sitter spacetimes, analyzing scattering features beyond spherical symmetry.

Findings

Significant differences in scattering characteristics for waves of different spins and angular momenta.

Deformation of the background geometry strongly affects grey-body factors and absorption cross-sections.

Exploration of the stability of the background geometry under deformation parameters.

Abstract

Recent developments in the gravitational waves interferometry require more pertinent theoretical models of gravitational waves generation and propagation. Untouched possible mechanisms of spin-2 spacetime perturbations production, we will consider their subsequent scattering on other black holes (BHs). Specifically, we consider a generalization of the Regge-Wheeler-Zerilli equations for the case of distorted BHs (BHs surrounded with matter) in Minkowski and Anti-de Sitter spacetimes, the metric potential of which obeys the Liouville equation. We establish significant differences in scattering characteristics of waves of different spins and angular momenta, including the gravitational waves, caused by losing the spherical symmetry of their propagation background. In particular, we demonstrate the strong impact of the background geometry deformation on the grey-body factors, hence on the absorption cross-sections of scattering waves, and explore the issue of stability of the background geometry upon changing the deformation degree parameters.