Scalar QNMs for higher dimensional black holes surrounded by quintessence in Rastall gravity

TL;DR

This paper derives higher-dimensional black hole solutions with quintessence in Rastall gravity and analyzes how the modified gravity affects scalar quasinormal modes, finding that low-density exotic matter does not induce instabilities.

Contribution

It provides the first calculation of scalar quasinormal modes for higher-dimensional black holes in Rastall gravity with exotic matter fields.

Findings

Mode shifts depend on the type of exotic matter.

Low-density matter does not cause instabilities in the modes.

The black hole solutions are valid in arbitrary dimensions.

Abstract

The spacetime solution for a black hole, surrounded by an exotic matter field, in Rastall gravity, is calculated in an arbitrary d-dimensional spacetime. After this, we calculate the scalar quasinormal modes of such solution, and study the shift on the modes caused by the modification of the theory of gravity, i.e., by the introduction of a new term due to Rastall. We conclude that the shift strongly depends on the kind of exotic field one is studying, but for a low density matter that supposedly pervades the universe, it is unlikely that Rastall gravity will cause any instability on the probe field.