Dirac quasinormal modes of Chern-Simons and BTZ black holes with torsion

TL;DR

This paper analytically investigates fermionic quasinormal modes of Chern-Simons and BTZ black holes with torsion, revealing how curvature and torsion influence oscillation and decay properties, confirming stability under perturbations.

Contribution

It provides the first analytical calculation of fermionic quasinormal modes for Chern-Simons black holes with torsion, highlighting the effects of curvature and torsion on mode frequencies.

Findings

Quasinormal modes depend on the highest curvature power in the theory.

Torsion modifies the real part of frequencies in five-dimensional black holes.

Torsion affects the imaginary part, influencing decay times in BTZ black holes.

Abstract

We study Chern-Simons black holes in d-dimensions and we calculate analytically the quasinormal modes of fermionic perturbations. Also, we consider as background the five-dimensional Chern-Simons black hole with torsion and the BTZ black hole with torsion. We have found that the quasinormal modes depend on the highest power of curvature present in the Chern-Simons theory, such as occurs for the quasinormal modes of scalar perturbations. We also show that the effect of the torsion is to modify the real part of the quasinormal frequencies, which modify the oscillation frequency of the field for the five dimensional case. However, for the BTZ black hole with torsion, the effect is to modify the imaginary part of these frequencies, that is, the relaxation time for the decay of the black hole perturbation. The imaginary part of the quasinormal frequencies is negative which guaranties the stability of these black holes under fermionic field perturbations.