Quasinormal spectra of higher dimensional regular black holes in theories with infinite curvature corrections

Abstract

We investigate the quasinormal modes of massless scalar and electromagnetic test fields propagating on several families of higher-dimensional regular black holes arising in gravitational theories with an infinite tower of higher-curvature corrections to Einstein gravity. Using the Wentzel--Kramers--Brillouin (WKB) method supplemented by Padé approximants, we compute the fundamental modes and derive compact analytic expressions in the eikonal regime. For all models considered, positive higher-curvature coupling reduces both the oscillation frequencies and damping rates relative to the corresponding singular general-relativistic limit. Since our analysis is restricted to test-field perturbations on fixed regular black-hole backgrounds, these results should be interpreted as geometric and phenomenological signatures of the background geometry rather than as gravitational perturbations of the full higher-curvature theory. Our results provide further insight into how quantum-gravity-inspired corrections and regularity conditions may affect black-hole ringdown signals.

18 pages, 3 figures