The quasinormal modes of Kerr-Newman black holes: a separated approach
Abstract
We compute Kerr-Newman quasinormal modes using a recently found exact separation of the gravitoelectric perturbation equations. For each spin-label ς=±1, a matrix angular ordinary differential equation and a scalar second-order radial ordinary differential equation define a joint spectral problem for the complex frequency ω and separation constant λ. We solve this problem by imposing regularity at the angular poles, ingoing behavior at the event horizon, and outgoing behavior at infinity. We benchmark the numerical code built to solve the separated equations, and the resulting frequencies, against recently published spectral calculations of the coupled system. Comparisons with those results yield absolute differences of order 10−10 to 10−5, depending on the BH parameters and overtone number. We also find numerical hints of spin-label isospectrality in both the electromagnetic-led and gravitational-led sectors of fundamental quasinormal modes, even at near-extremal Kerr-Newman configurations. These results provide numerical evidence that the separated equations reproduce Kerr-Newman quasinormal frequencies and offer a practical route to exploring the ringdown of rotating, charged black holes.
Related
- Quasinormal modes of Kerr-Newman-de Sitter black holes from Heun connection formulae
- Quasinormal modes of massive scalar perturbations in slow-rotation bumblebee black holes with traceless conformal electrodynamics
- Quasinormal modes of rotating black holes with ultralight scalar fields
- Phase transitions and quasinormal modes of Euler-Heisenberg-dilaton AdS black holes
- Axial gravitational quasinormal modes of magnetically charged black holes
BibTeX
@misc{destounis2026quasinormal,
title = {{The quasinormal modes of Kerr-Newman black holes: a separated approach}},
author = {Kyriakos Destounis and Vitor Cardoso and Peter Hintz},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07142},
eprint = {2610.07142},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07142},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The quasinormal modes of Kerr-Newman black holes: a separated approach
AU - Kyriakos Destounis
AU - Vitor Cardoso
AU - Peter Hintz
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.07142
UR - https://arxiv.org/abs/2610.07142
AB - We compute Kerr-Newman quasinormal modes using a recently found exact separation of the gravitoelectric perturbation equations. For each spin-label ς=±1, a matrix angular ordinary differential equation and a scalar second-order radial ordinary differential equation define a joint spectral problem for the complex frequency ω and separation constant λ. We solve this problem by imposing regularity at the angular poles, ingoing behavior at the event horizon, and outgoing behavior at infinity. We benchmark the numerical code built to solve the separated equations, and the resulting frequencies, against recently published spectral calculations of the coupled system. Comparisons with those results yield absolute differences of order 10^−10 to 10^−5, depending on the BH parameters and overtone number. We also find numerical hints of spin-label isospectrality in both the electromagnetic-led and gravitational-led sectors of fundamental quasinormal modes, even at near-extremal Kerr-Newman configurations. These results provide numerical evidence that the separated equations reproduce Kerr-Newman quasinormal frequencies and offer a practical route to exploring the ringdown of rotating, charged black holes.
ER -