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arXiv · 1708.06037

Superradiance of charged black holes in Einstein-Gauss-Bonnet Gravity

Octavio Fierro·Nicolas Grandi·Julio Oliva
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Abstract

In this paper we show that electrically charged black holes in Einstein-Gauss-Bonnet gravity suffer from a superradiant instability. It is triggered by a charged scalar field that fulfills Dirichlet boundary conditions at a mirror located outside the horizon. As in General Relativity, the unstable modes exist provided the mirror is located beyond a critical radius, making the instability a long wavelength one. We explore the effects of the Gauss-Bonnet corrections on the critical radius and find evidence that the critical radius decreases as the Gauss-Bonnet coupling $\alpha$ increases. Due to the, up to date, lack of an analytic rotating solution for Einstein-Gauss-Bonnet theory, this is the first example of a superradiant instability in the presence of higher curvature terms in the action.

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Octavio Fierro, Nicolas Grandi, Julio Oliva. 2017-08-21. Superradiance of charged black holes in Einstein-Gauss-Bonnet Gravity. https://doi.org/10.1088/1361-6382%2Faab3f6

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