Black Hole Perturbation Approach to Gravitational Radiation

Abstract

It is expected that the near future large-scale laser interferometers such as LIGO, VIRGO, GEO600 and TAMA300 will directly detect gravitational waves from various astrophysical sources [1]. Consequently there is a growing interest in the study of sources of gravitational waves in the universe and the most promising detectable source is the gravitational radiation from a compact binary, in particular a neutron star — neutron star (NS-NS) binary, during the final phase of its inspiralling The orbit of a compact binary will gradually spiral in due to gravitational radiation and its frequency will eventually sweep through the detectable frequency range of those interferometers, approximately 10 Hz to 1000 Hz, before the coalescence. To extract out the information contained in thus detected gravitational waves efficiently as well as correctly, it has therefore become very important to know the detailed evolution of an inspiralling binary and to construct accurate theoretical templates for the waveforms. Since the orbital velocity v will be relativistic (v ≳ 0.1c for a NS-NS binary) when the gravitational waves become detectable, a simple estimate based on the Newtonian quadrupole formula is insufficient; instead we must take into account the relativistic corrections seriously.