Scalar and electromagnetic perturbations of nonsingular nonrotating black holes in conformal gravity

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