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arXiv · 1205.3184

Tidal acceleration of black holes and superradiance

Vitor Cardoso·Paolo Pani
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Abstract

Tidal effects have long ago locked the Moon in synchronous rotation with the Earth and progressively increase the Earth-Moon distance. This "tidal acceleration" hinges on dissipation. Binaries containing black holes may also be tidally accelerated, dissipation being caused by the event horizon - a flexible, viscous one-way membrane. In fact, this process is known for many years under a different guise: superradiance. In General Relativity, tidal acceleration is obscured by gravitational-wave emission. However, when coupling to light scalar degrees of freedom is allowed, an induced dipole moment produces a "polarization acceleration", which might be orders of magnitude stronger than tidal quadrupolar effects. Consequences for optical and gravitational-wave observations are intriguing and it is not impossible that imprints of such mechanism have already been observed.

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Vitor Cardoso, Paolo Pani. 2013-01-17. Tidal acceleration of black holes and superradiance. https://doi.org/10.1088/0264-9381%2F30%2F4%2F045011

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