Radiation emitted by a source orbiting a Schwarzschild--anti--de Sitter black hole

TL;DR

This paper investigates scalar radiation from a source orbiting a Schwarzschild--anti--de Sitter black hole, revealing how the emitted power varies with boundary conditions and spacetime parameters, and comparing it to other black hole spacetimes.

Contribution

It provides the first detailed analysis of scalar radiation emission in Schwarzschild--anti--de Sitter spacetime with reflective boundary conditions, highlighting differences from Schwarzschild and Schwarzschild--de Sitter cases.

Findings

Enhanced power in lower multipole modes for Schwarzschild--de Sitter.

Enhanced power in higher multipole modes for Schwarzschild--anti--de Sitter.

Comparison of emitted power across different spacetime geometries.

Abstract

We study the scalar radiation emitted by a source orbiting a Schwarzschild--anti--de Sitter black hole in circular geodesics. We obtain the emitted power using quantum field theory in curved spacetimes at tree level with reflective boundary conditions at infinity. We compare our results with the ones obtained in Schwarzschild and Schwarzschild--de Sitter ($\Lambda > 0$) spacetimes. In the Schwarzschild-de Sitter spacetime we observe an enhancement of the emitted power associated to the lower multipole modes, when compared with the Schwarzschild case. In contrast, for the Schwarzschild-anti-de Sitter spacetime, the enhancement is rather of the higher multipole modes.