Scalar and Dirac perturbations of the Reissner-Nordstrom black hole and Painleve transcendents

We investigate spin-0 and spin -21 perturbations for nonextremal and extremal Reissner-Nordstrom 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.

Automated summary

The study investigates spin perturbations for nonextremal and extremal Reissner-Nordstrom backgrounds using the isomonodromic method. By calculating the fundamental quasinormal modes associated with each perturbation, the study reveals the existence of nondamping modes for qQ above a spin-dependent critical value and determines the bifurcation point in the q - Q parameter space.