Physics of black hole binaries: Geodesics, relaxation modes, and energy extraction

  title={Physics of black hole binaries: Geodesics, relaxation modes, and energy extraction},
  author={L. Bernard and Vitor Cardoso and Taishi Ikeda and Miguel Zilh{\~a}o},
  journal={Physical Review D},
Black holes are the simplest macroscopic objects, and provide unique tests of General Relativity. They have been compared to the Hydrogen atom in quantum mechanics. Here, we establish a few facts about the simplest systems bound by gravity: black hole binaries. We provide strong evidence for the existence of `global' photosurfaces surrounding the binary, and of binary quasinormal modes leading to exponential decay of massless fields when the binary spacetime is slightly perturbed. These two… 
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