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The Washington University Gravitation Group (WUGRAV) of Professors Will and Suen,
and their post-doctoral fellows and students study the observable
aspects of general relativity. A central current thrust is to calculate the gravitational radiation from inspiralling and merging binary systems of compact objects (neutron stars or black holes). These are the most promising sources of gravitational waves detectable by large-scale laser-interferometric gravitational-wave observatories, such as the LIGO observatories in the United States. Important astronomical information can be extracted from the detected signals by comparing them against theoretical "template" waveforms that have been calculated to high precision using general relativity. For the inspiral phase, the group is calculating the waveforms using high-order versions of the so-called "post-Newtonian" approximation to general relativity. Professor Will is leading an international effort in pushing the post-Newtonian treatment to an accuracy high enough for the data analysis of the LIGO project. For the final merger of the two black holes or neutron stars, when approximation methods break down because of strongly nonlinear relativistic effects, the physics has to be studied through numerical simulations. Professor Suen is leading an effort in solving the full set of Einstein equations numerically, coupled with relativistic hydrodynamics and with input from nuclear astrophysics. The simulations being carried out will have implications not just for gravitational-wave astronomy but also for X-ray and Gamma-ray astronomies, both exciting frontiers driven by the large amount of recent satellite data. The multidisciplinary work involves general relativity, astrophysics, nuclear physics, massively parallel computing, applied mathematics, and numerical analysis. The Gravity Group is also part of the McDonnell Center for the Space Sciences. |
Gravitational Physics