Gravitational Radiation and Relativistic Astrophysics

California Institute Of Technology, Pasadena CA

Investigators

Abstract

Theoretical and computational research will be carried out in support of LIGO, the Laser Interferometer Gravitational Wave Observatory: (1) Research close to experiment, e.g. analysis of and methods to reduce thermal noise, light scattering noise, and opto- mechanical instabilities. (2) Development of numerical-relativity tools for simulating gravitational-wave sources, especially a computer code based on pseudo-spectral methods that is robust, highly accurate, and very efficient. (3) Use of this code and other theoretical methods to develop insights into gravitational wave sources, and especially predict their emitted waveforms. Among the sources to be studied are (a) the slow inspiral of neutron stars and small black holes into intermedicate-mass black holes ("Extreme mass ratio inspirals" or EMRIs), (b) the late inspiral of black-hole binaries including spin-orbit and spin-spin interactions and possible spin flips, (c) the transition from inspiral to plunge in black-hole binaries, (d) the merger of black-hole binaries, and (d) rotating neutron stars. (4) Use of the insights about sources developed in this work to construct better template families for searching for the waves, and improved techniques for extracting information carried by the waves. (5) Participation in the LIGO Scientific Collaboration's gravitational wave searches, using these templates and techniques as well as others. This research is designed to help make LIGO a success by (i) increasing its prospects of detecting gravitational waves from a wide variety of sources, and (ii) improving its ability to extract from observed waves the rich information that the waves should carry. It will also contribute to the advance of technology and techniques for high-precision measurement, contribute to our understanding of astrophysical systems, and contribute to the development of numerical methods and computer codes capable of carrying out robust and accurate simulations of highly dynamical spacetimes. This research will be carried out in large measure by about ten graduate students and six postdoctoral students. This program's diversity of types of research and research tools will provide a rich training ground for these students.