COLLISIONS OF BOOSTED BLACK-HOLES - PERTURBATION-THEORY PREDICTION OFGRAVITATIONAL-RADIATION

We consider general relativistic Cauchy data representing two nonspinn ing, equal-mass black holes boosted toward each other, When the black holes are close enough to catch other and their momentum is Sufficient ly high, an encompassing apparent horizon is present so the system can be viewed as a single, perturbed black hole. We employ gauge-invarian t perturbation theory and integrate the Zerilli equation to analyze th ese time-asymmetric data sets and compute gravitational waveforms and emitted energies. When coupled with a simple Newtonian analysis of the infall trajectory, we find striking agreement between the perturbatio n calculation of emitted energies and the results of fully general rel ativistic numerical simulations of time-symmetric initial data.