Graviton Emission in the Bulk by a Simply Rotating Black Hole

TL;DR

This paper investigates gravitational tensor mode emissions from higher-dimensional rotating black holes, providing analytical and numerical solutions for emission rates and their dependence on black hole parameters.

Contribution

It offers the first combined analytical and numerical analysis of graviton emission from rotating black holes in higher dimensions, including mode multiplicities and parameter dependencies.

Findings

Analytical solutions match numerical results at low energies.

Emission rates depend on the number of extra dimensions and black hole spin.

Identifies the dominant modes contributing to graviton emission.

Abstract

In this work, we study the emission of tensor-type gravitational degrees of freedom from a higher-dimensional, simply rotating black hole in the bulk. The decoupled radial part of the corresponding field equation is first solved analytically in the limit of low-energy emitted particles and low-angular momentum of the black hole in order to derive the absorption probability. Both the angular and radial equations are then solved numerically, and the comparison of the analytical and numerical results show a very good agreement in the low and intermediate energy regimes. By using our exact, numerical results we compute the energy and angular momentum emission rates and their dependence on the spacetime parameters such as the number of additional spacelike dimensions and the angular momentum of the black hole. Particular care is given to the convergence of our results in terms of the number of modes taken into account in the calculation, and the multiplicity of graviton tensor modes that correspond to the same angular-momentum numbers.