Action principle formulation for the motion of extended bodies in general relativity

We present an action principle formulation for the study of the motion of an extended body in general relativity in the limit of a weak gravitational field. This gives the classical equations of motion for multipole moments of arbitrary order coupling to the gravitational field. In particular, a new force due to the octupole moment is obtained. The action also yields the gravitationally induced phase shifts in quantum interference experiments due to the coupling of all multipole moments.