The fastest relaxation rate of higher-dimensional Reissner–Nordström black hole

In the eikonal regime, we analytically calculate quasinormal resonance frequencies for massless scalar perturbations of the higher-dimensional Reissner–Nordström (RN) black holes. Remarkably, we find that the higher-dimensional RN black holes coupled with the massless scalar fields have the fastest relaxation rates in the Schwarzschild limit, this is qualitatively different from the four-dimensional case where the black hole with non-vanishing charge has the fastest relaxation rate. Keywords: Massless scalar field, Higher-dimensional Reissner–Nordström black hole, Quasinormal mode