Measuring black-hole parameters and testing general relativity using gravitational-wave data from space-based interferometers

摘要

Among the expected sources of gravitational waves for the LaserInterferometer Space Antenna (LISA) is the capture of solar-mass compact starsby massive black holes residing in galactic centers. We construct a simplemodel for such a capture, in which the compact star moves freely on a circularorbit in the equatorial plane of the massive black hole. We consider thegravitational waves emitted during the late stages of orbital evolution,shortly before the orbiting mass reaches the innermost stable circular orbit.We construct a simple model for the gravitational-wave signal, in which thephasing of the waves plays the dominant role. The signal's behavior depends ona number of parameters, including $\mu$, the mass of the orbiting star, $M$,the mass of the central black hole, and $J$, the black hole's angular momentum.We calculate, using our simplified model, and in the limit of largesignal-to-noise ratio, the accuracy with which these quantities can beestimated during a gravitational-wave measurement. Our simplified model alsosuggests a method for experimentally testing the strong-field predictions ofgeneral relativity.