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arXiv · 2201.11138

Extremal Charged Black Holes and Superradiantly Unstable Quasinormal Modes

Zhan-Feng Mai·Run-Qiu Yang·H. Lü
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Abstract

It was recently shown that the extremal charged black holes in STU supergravity suffer from superradiant instability owing to the existence of the unstable (low-frequency) quasibound states associated with a charged massive scalar field. In this paper, we show numerically that for some charge configurations, these black holes can also excite the (higher-frequency) superradiantly unstable quasinormal modes. We find empirically that the unstable modes are closely related to having a volcano-shaped effective potential in the Schr\"odinger-like wave equation.

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Zhan-Feng Mai, Run-Qiu Yang, H. Lü. 2022-01-26. Extremal Charged Black Holes and Superradiantly Unstable Quasinormal Modes. https://doi.org/10.1140/epjc/s10052-022-10490-y

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