Hamiltonian formulation of time-dependent variational principles for the many-body system

We discuss a canonical Hamiltonian formulation for the general time-dependent variational principle associated with the Schroedinger equation. It is expected that such methods will be useful for a wide range of systems including the many body problem and field theory. It is hoped that the canonical formulation will be an aid in identifying useful further approximation schemes for complicated systems; for example, the reduction to some sort of fluid dynamics for the many body scattering problem or the identification of suitable dissipation terms in a reduced description by the use of statistical arguments.