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arXiv · 2408.13964

Massive scalar perturbations in Kerr Black Holes: near extremal analysis

João Paulo Cavalcante·Maurício Richartz·Bruno Carneiro da Cunha
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Abstract

We study quasinormal modes of massive scalar perturbations in Kerr black holes using the isomonodromic method. For arbitrary scalar masses $M \mu$ and black hole spins $a/M$, we numerically determine the quasinormal frequencies for various orbital $\ell$, azimuthal $m$, and overtone $n$ numbers. In particular, we derive an analytic expression for frequencies of the zero-damping modes near the extremal limit $a/M \rightarrow 1$. For $\ell=m=1$, we reveal that the fundamental mode becomes a damped mode (rather than a zero-damping mode) if the scalar field is sufficiently heavy. By exploring the parameter space, we find numerical evidence for level-crossing between the longest-living mode and the first overtone at an exceptional point $(M\mu)_c \simeq 0.3704981$ and $(a/M)_c\simeq 0.9994660$.

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João Paulo Cavalcante, Maurício Richartz, Bruno Carneiro da Cunha. 2024-08-26. Massive scalar perturbations in Kerr Black Holes: near extremal analysis. https://doi.org/10.1103/physrevd.110.124064

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