Black hole collision with a scalar particle in four, five and seven dimensional anti-de Sitter spacetimes: ringing and radiation

TL;DR

This study analyzes scalar radiation emitted during the infall of a test particle into higher-dimensional anti-de Sitter black holes, revealing spectral peaks at specific frequencies and exponential waveform decay linked to quasinormal modes, with implications for black hole physics and AdS/CFT.

Contribution

It extends previous analyses to higher dimensions (4, 5, 7) for scalar radiation from black hole collisions, providing new spectral and waveform insights relevant to AdS/CFT and black hole formation scenarios.

Findings

Spectral peaks at frequency ~d-1 for small black holes

Waveforms decay exponentially governed by quasinormal frequencies

Results relevant for AdS/CFT and black hole production at LHC

Abstract

In this work we compute the spectra, waveforms and total scalar energy radiated during the radial infall of a small test particle coupled to a scalar field into a $d$-dimensional Schwarzschild-anti-de Sitter black hole. We focus on $d=4, 5$ and 7, extending the analysis we have done for $d=3$. For small black holes, the spectra peaks strongly at a frequency $\omega \sim d-1$, which is the lowest pure anti-de Sitter (AdS) mode. The waveform vanishes exponentially as $t \to \infty$, and this exponential decay is governed entirely by the lowest quasinormal frequency. This collision process is interesting from the point of view of the dynamics itself in relation to the possibility of manufacturing black holes at LHC within the brane world scenario, and from the point of view of the AdS/CFT conjecture, since the scalar field can represent the string theory dilaton, and 4, 5, 7 are dimensions of interest for the AdS/CFT correspondence.