Quasinormal modes for tensorial perturbation of Gauss Bonnet black holes using third order WKB approach

We obtain the quasinormal modes for tensor perturbations of Gauss-Bonnet black holes in d = 5, 7, 8 dimension using third order WKB formalism. The black hole in d = 6 is not considered because of the fact that it is unstable to tensor mode perturbations. For the uncharged Gauss-Bonnet black hole the real part of the frequency increases as the GaussBonnet coupling (α) increases. The imaginary part first decreases upto a certain value of α and then increases with α. It has also been shown that as α → 0, the quasinormal mode frequency for tensor perturbation of the Schwarzschild black hole is obtained. We have also calculated the quasinormal spectrum of the charged Gauss-Bonnet black hole and has found that the real oscillation frequency increases as the charge of the black hole is increased and the damping rate, i.e. the imaginary part of the frequency falls down with the increase of the charge.