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arXiv · 1304.2836

Numerical simulations of single and binary black holes in scalar-tensor theories: circumventing the no-hair theorem

Emanuele Berti·Vitor Cardoso·Leonardo Gualtieri·Michael Horbatsch·Ulrich Sperhake
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Abstract

Scalar-tensor theories are a compelling alternative to general relativity and one of the most accepted extensions of Einstein's theory. Black holes in these theories have no hair, but could grow "wigs" supported by time-dependent boundary conditions or spatial gradients. Time-dependent or spatially varying fields lead in general to nontrivial black hole dynamics, with potentially interesting experimental consequences. We carry out a numerical investigation of the dynamics of single and binary black holes in the presence of scalar fields. In particular we study gravitational and scalar radiation from black-hole binaries in a constant scalar-field gradient, and we compare our numerical findings to analytical models. In the single black hole case we find that, after a short transient, the scalar field relaxes to static configurations, in agreement with perturbative calculations. Furthermore we predict analytically (and verify numerically) that accelerated black holes in a scalar-field gradient emit scalar radiation. For a quasicircular black-hole binary, our analytical and numerical calculations show that the dominant component of the scalar radiation is emitted at twice the binary's orbital frequency.

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Emanuele Berti, Vitor Cardoso, Leonardo Gualtieri, Michael Horbatsch, Ulrich Sperhake. 2013-06-13. Numerical simulations of single and binary black holes in scalar-tensor theories: circumventing the no-hair theorem. https://doi.org/10.1103/physrevd.87.124020

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