Scalar and Dirac perturbations of the Reissner-Nordström black hole and Painlevé transcendents
Published in Phys. Rev. D 104, 124040, 2021
We investigate spin-0 and spin-1/2 perturbations for nonextremal and extremal Reissner-Nordström backgrounds using the isomonodromic method. We calculate the fundamental quasinormal modes (QNMs) associated with each perturbation as a function of the electromagnetic coupling qQ and ratio Q/M. After corroborating the literature values for generic qQ and Q/M, we turn to study the near-extremal limit. In parallel with the study of QNMs for the Kerr geometry, we find the existence of “nondamping” modes for qQ above a spin-dependent critical value and locate the bifurcation point in the q−Q parameter space.
Paper https://journals.aps.org/prd/abstract/10.1103/PhysRevD.104.124040