# Scalar perturbations of nonsingular nonrotating black holes in conformal gravity

## TL;DR

This paper investigates the stability and quasinormal modes of nonsingular black holes in conformal gravity, showing electromagnetic perturbations are unaffected by the scaling factor, and scalar perturbations suggest potential observational tests.

## Contribution

It introduces a family of nonsingular black hole solutions in conformal gravity and analyzes their perturbations, highlighting stability and observational implications.

## Key findings

- Black holes are stable under scalar and electromagnetic perturbations.
- Electromagnetic quasinormal modes match Schwarzschild's spectrum.
- Scalar perturbations depend on the scaling factor, affecting potential observations.

## Abstract

We study scalar and electromagnetic perturbations of a family of nonsingular nonrotating black hole spacetimes that are solutions in a large class of conformally invariant theories of gravity. The effective potential for scalar perturbations depends on the exact form of the scaling factor. Electromagnetic perturbations do not feel the scaling factor, and the corresponding quasinormal mode spectrum is the same as in the Schwarzschild metric. We find that these black hole metrics are stable under scalar and electromagnetic perturbations. Assuming that the quasinormal mode spectrum for scalar perturbations is not too different from that for gravitational perturbations, we can expect that the calculation of the quasinormal mode spectrum and the observation with gravitational wave detectors of quasinormal modes from astrophysical black holes can constrain the scaling factor and test these solutions.