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General Relativity and Quantum Cosmology, gr-qc, Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE,High Energy Physics - Theory, hep-th
Abstract:
The generation of a large recoil velocity from the inspiral and merger of
binary black holes represents one of the most exciting results of
numerical-relativity calculations. While many aspects of this process have been
investigated and explained, the "anti-kick", namely the sudden deceleration
after the merger, has not yet found a simple explanation. We show that the
anti-kick can be easily understood in terms of the radiation from a deformed
black hole where the intrinsically anisotropic curvature distribution on the
horizon determines the direction and intensity of the recoil. Our analysis is
focussed on the properties of Robinson-Trautman spacetimes and allows us to
measure both the energies and momenta radiated in a gauge-invariant manner. At
the same time, this simpler setup provides all the qualitative but also
quantitative features of inspiralling black hole binaries, thus opening the way
to a deeper understanding of the nonlinear dynamics of black-hole spacetimes.
