Quasinormal modes of black holes in Weyl gravity: electromagnetic and gravitational perturbations

The recent reported gravitational wave detection motivates one to investigate the properties of different black hole models, especially their behavior under (axial) gravitational perturbation. Here, we study the quasinormal modes of black holes in Weyl gravity. We derive the master equation describing the quasinormal radiation by using a relation between the Schwarzschild-anti de Sitter black holes and Weyl solutions, and also the conformal invariance property of the Weyl action. It will be observed that the quasinormal mode spectra of the Weyl solutions deviate from those of the Schwarzschild black hole due to the presence of an additional linear r-term in the metric function. We also consider the evolution of the Maxwell field on the background spacetime and obtain the master equation of electromagnetic perturbations. Then, we use the WKB approximation and asymptotic iteration method to calculate the quasinormal frequencies. Finally, the time evolution of modes is studied through the time-domain integration of the master equation.