Space-based gravitational wave astrophysics.

摘要

In the near future, several Earth-based and space-based gravitational wave observatories will be completed. With this imminent change in the tools available to observe the Universe, there is much work to be done in describing the fundamental response of our instruments to gravitational radiation, understanding the sources of gravitational radiation, and determining what can be learned about the fundamental nature of the gravitational interaction from the detection of these waves.; The first original result reported here is the determination of the sensitivity limits of a spaceborne gravitational wave observatory. Determining if particular sources of gravitational radiation are detectable by a specific gravitational observatory requires knowledge of the sensitivity limits of the instrument, commonly depicted as a graph of the spectral density of the dimensionless strain vs. frequency of the gravitational wave. Previous discussions of the sensitivity have relied on approximations and heuristic arguments about the shape of the transfer function to construct a sensitivity curve. This thesis details the computation of the exact sensitivity curve given a simple set of parameters describing a space-based interferometer.; The second original result presented here is an exploration of how the mass of the graviton (the fundamental quanta of the gravitational field) might be determined from observations of known sources of gravitational radiation with a space-based interferometric observatory. Current experimental limits place an upper bound on the Compton wavelength of the graviton at $lg2.8\times 1012$ km, based on analysis of Yukawa violations to Newton's Universal law of gravitation in the solar system. The advent of state-of-the-art space-based gravitational wave interferometers will allow new bounds to be placed on the graviton mass by observing interacting white dwarf binary stars, such as AM CVn (AM Canum Venaticorum). If the graviton is massless, experimental uncertainty will be the limiting factor in computing bounds on the graviton mass. For space-based interferometric detectors, the predicted uncertainties in the observations of AM CVn will place an upper bound on the inverse mass of the graviton of $lg1.4\times 1015$ km.