Tidal acceleration of black holes and superradiance
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.
Keywords
Cite
@article{arxiv.1205.3184,
title = {Tidal acceleration of black holes and superradiance},
author = {Vitor Cardoso and Paolo Pani},
journal= {arXiv preprint arXiv:1205.3184},
year = {2015}
}
Comments
12 pages, 4 figures. v2: minor changes. Final version to appear in CQG