Gravitational Waves: Elusive Cosmic Messengers

Abstract

The final merger of two black holes is expected to be the strongest g ravitational wave source for ground-based interferometers such as LIG O, VIRGO, and GE0600, as well as the space-based interferometer LISA. Observing these sources with gravitational wave detectors requires t hat we know the radiation waveforms they emit. Since these mergers ta ke place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate t hese waveforms. For more than 30 years, scientists have tried to comp ute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could comple te even a single orbit. Within the past few years, however, this situ ation has changed dramatically, with a series of remarkable breakthro ughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applic ations in gravitational wave detection, data analysis, and astrophysi cs.