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arXiv · 1607.06304

Dynamical formation of a Reissner-Nordstr\"om black hole with scalar hair in a cavity

Nicolas Sanchis-Gual·Juan Carlos Degollado·Carlos Herdeiro·José A. Font·Pedro J. Montero
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Abstract

In a recent letter, we presented numerical relativity simulations, solving the full Einstein--Maxwell--Klein-Gordon equations, of superradiantly unstable Reissner-Nordstr\"om black holes (BHs), enclosed in a cavity. Low frequency, spherical perturbations of a charged scalar field, trigger this instability. The system's evolution was followed into the non-linear regime, until it relaxed into an equilibrium configuration, found to be a $\textit{hairy}$ BH: a charged horizon in equilibrium with a scalar field condensate, whose phase is oscillating at the (final) critical frequency. Here, we investigate the impact of adding self-interactions to the scalar field. In particular, we find sufficiently large self-interactions suppress the exponential growth phase, known from linear theory, and promote a non-monotonic behaviour of the scalar field energy. Furthermore, we discuss in detail the influence of the various parameters in this model: the initial BH charge, the initial scalar perturbation, the scalar field charge, mass, and the position of the cavity's boundary (mirror). We also investigate the "explosive" non-linear regime previously reported to be akin to a bosenova. A mode analysis shows that the "explosions" can be interpreted as the decay into the BH of modes that exit the superradiant regime.

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Nicolas Sanchis-Gual, Juan Carlos Degollado, Carlos Herdeiro, José A. Font, Pedro J. Montero. 2016-07-21. Dynamical formation of a Reissner-Nordstr\"om black hole with scalar hair in a cavity. https://doi.org/10.1103/physrevd.94.044061

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