CALCULATION OF GRAVITATIONAL WAVE-FORMS FROM BLACK-HOLE COLLISIONS AND DISK COLLAPSE - APPLYING PERTURBATION-THEORY TO NUMERICAL SPACETIMES

Many simulations of gravitational collapse to black holes become inaccurate before the total emitted gravitational radiation can be determined. The main difficulty is that a significant component of the radiation is still in the near-zone, strong field region at the time the simulation breaks down. We show how to calculate the emitted waveform by matching the numerical simulation to a perturbation solution when the final state of the system approaches a Schwarzschild black hole. We apply the technique to two scenarios: the head-on collision of two black holes and the collapse of a disk to a black hole. This is the first reasonably accurate calculation of the radiation generated from colliding black holes that form from matter collapse. © 1995 The American Physical Society.