The nation has committed substantial resources to making gravitational-wave astronomy a reality. Proposed research of Friedman and collaborators will advance understanding of problems in gravitational-wave astronomy and allied areas of general relativistic astrophysics. (1) Tools developed with support of the previous grant will be used in the construction of initial data and quasiequilibrium sequences of neutron stars and black holes, following two related approaches: Solutions with helical symmetry of the full Einstein equation (with equal amounts of ingoing and outgoing radiation) and a waveless approximation in which second time derivatives of the metric are neglected in constructing solutions. (2) Work on the inspiral of a small black hole orbiting a supermassive black hole seeks to generalize a renormalization prescription to gauges tied to solutions to the Teukolsky equation and to compute the self-force on a point-mass. (3) Several additional problems involve oscillations and stability (dynamical and gravitational-wave driven instabilities) of rapidly rotating relativistic stars and of accretion tori about black holes. Postdoctoral associates, graduate students, and REU undergraduates will gain numerical and analytical expertise in leading problems in general relativistic astrophysics. Results of research will be broadly disseminated in lectures, a book in progress on rotating relativistic stars, and popular talks.
