COMPUTING THE MERGER OF BLACK-HOLE BINARIES - THE IBBH PROBLEM - ART.NO. 061501

Gravitational radiation arising from the inspiral and merger of binary black holes (BBH's) is a promising candidate for detection by kilomet er-scale interferometric gravitational wave observatories. This Rapid Communication discusses a serious obstacle to searches for such radiat ion and to the interpretation of any observed waves: the inability of current computational techniques to evolve a BBH through its last simi lar to 10 orbits of inspiral (similar to 100 radians of gravitational- wave phase). A new set of numerical-relativity techniques is proposed for solving this ''intermediate binary black hole'' (IBBH) problem: (i ) numerical evolutions performed in coordinates co-rotating with the B BH, in which the metric coefficients evolve on the long timescale of i nspiral, and (ii) techniques for mathematically freezing out gravitati onal degrees of freedom that are not excited by the waves. [S0556-2821 (98)50218-4].