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arXiv · 2112.05669

Existence of Zero-damped Quasinormal Frequencies for Nearly Extremal Black Holes

Jason Joykutty
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Abstract

It has been observed that many spacetimes which feature a near-extremal horizon exhibit the phenomenon of zero-damped modes. This is characterised by the existence of a sequence of quasinormal frequencies which all converge to some purely imaginary number $i\alpha$ in the extremal limit and cluster in a neighbourhood of the line $\Im s=\alpha$. In this paper, we establish that this property is present for the conformal Klein-Gordon equation on a Reissner-Nordstr\"om-de Sitter background. This follows from a similar result that we prove for a class of spherically symmetric black hole spacetimes with a cosmological horizon. We also show that the phenomenon of zero-damped modes is stable to perturbations that arise through adding a potential.

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Jason Joykutty. 2021-12-10. Existence of Zero-damped Quasinormal Frequencies for Nearly Extremal Black Holes. https://doi.org/10.1007/s00023-022-01202-z

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