Parametric excitation of spinning test particles by gravitational waves

One of the most striking predictions of Einstein's theory of gravitation is the existence of gravitational waves. Such waves are thought to be produced by astrophysical phenomena ranging from the coalescence of orbiting binaries to violent events in the early Universe. Their detection would herald a new window for the observation of natural phenomena. The essential mechanism by which gravitational waves interact with matter relies on the existence of "tidal forces" produced on extended structures in a non-uniform gravitational field. It has long been known that the angular momentum of rotating bodies can couple to gravitational curvature producing forces and torques. If one neglects the back-reaction of such bodies on the field itself a coherent multipole expansion has been developed by Dixon that rationalises a lot of early work on the classical motion of spinning particles in gravitational fields. These equations have been used to explore the effects of spherically and axially symmetric stationary gravitational fields on both massive and massless spinning test particles. An alternative approach has been adopted with results that differ significantly from those discussed here