Multipartition generalizations of the Schwinger variational principle

Generalizations of the Schwinger variational principle are proposed which include rearrangement scattering. Functionals are given for the transition amplitude. The requirement that a functional be stationary with respect to variation of the scattering wave function leads to a set of simultaneous equations for the scattering wave function rather than a single equation. This is consistent with recent formalisms for many-body scattering. (orig.)