Studies are continued and extended of the potentially observable consequences of the general theory of relativity, in experimental, astrophysical and cosmological contexts. A study of the inspiral and coalescence of binary systems of compact objects (neutron stars or black holes) and of the gravitational radiation emitted will be continued, using high- order post-Newtonian approximations to general relativity. The results will be of importance to the U.S. Laser Interferometric Gravitational Observatory (LIGO). Professor Will will study the possibility of placing a complete observational bound on post-Newtonian metric gravity using current observations and minimal theoretical assumptions. Studies of tests of the Einstein equivalence principle will continue, including tests of the isotropy of the one-way speed of light and tests of a nonsymmetric spacetime metric using trapped atoms. The cosmological effects of massive scalar fields, whose coupling to gravity produces a rapidly oscillating Newtonian coupling constant will be studied, as will the effects of relic gravitational perturbations emerging from the very early universe in "squeezed" quantum states.
