POST-NEWTONIAN EXPANSION OF GRAVITATIONAL-WAVES FROM A PARTICLE IN CIRCULAR ORBITS AROUND A ROTATING BLACK-HOLE - EFFECTS OF BLACK-HOLE ABSORPTION

When a particle moves around a Kerr black hole, it radiates gravitatio nal waves. Some of these waves are absorbed by the black hole. We calc ulate 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 e quation developed by Mane, Suzuki and Takasugi. We obtain the energy a bsorption rate to O((v/c)(8)) compared to the lowest order. We find th at the black hole absorption occurs at O((v/c)(5)) beyond the Newtonia n-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. Usin g the energy absorption rate, we investigate its effects on the orbita l evolution of coalescing compact binaries.