# Spectroscopy of extremal and near-extremal Kerr black holes

@article{Casals2019SpectroscopyOE,
title={Spectroscopy of extremal and near-extremal Kerr black holes},
author={M. Casals and L. F. L. Micchi},
journal={Physical Review D},
year={2019},
volume={99}
}
• Published 2019
• Physics
• Physical Review D
• We investigate linear, spin-field perturbations of Kerr black holes in the extremal limit throughout the complex-frequency domain. We calculate quasi-normal modes of extremal Kerr, as well as of near-extremal Kerr, via a novel approach: using the method of Mano, Suzuki and Takasugi (MST). We also show how, in the extremal limit, a branch cut is formed at the superradiant-bound frequency, $\omega_{SR}$, via a simultaneous accumulation of quasi-normal modes and totally-reflected modes. For real… CONTINUE READING