Post-Newtonian expansion of gravitational waves from a particle in circular orbits around a rotating black hole - Effects of black hole absorption

摘要

When a particle moves around a Kerr black hole, it radiates gravitational waves. Some of these waves are absorbed by the black hole. We calculate such absorption of gravitational waves induced by a particle of mass mu in a circular orbit on an equatorial plane around a Kerr black hole of mass M. We assume that the velocity of the particle v is much smaller than the speed of light c and calculate the energy absorption rate analytically. We adopt an analytic technique for the Teukolsky equation developed by Mane, Suzuki and Takasugi. We obtain the energy absorption rate to O((v/c)(8)) compared to the lowest order. We find that the black hole absorption occurs at O((v/c)(5)) beyond the Newtonian-quadrupole luminosity at infinity in the case when the black hole is rotating, which is O((v/c)(3)) lower than the non-rotating case. Using the energy absorption rate, we investigate its effects on the orbital evolution of coalescing compact binaries.