Admissible boundary conditions for Hamiltonian field theories

Abstract

In the setting of a multisymplectic formalism for Hamiltonian theories on manifolds with boundary a class of admissible boundary conditions based on the principle of preservation of the gauge symmetries of the theory is presented. Such admissible conditions are characterized as those boundary conditions determined by Lagrangian submanifolds on the space of fields at the boundary lying in the zero level set of the moment map of the group of gauge transformations at the boundary. The examples of gauge covariant fields and pure Yang–Mills theories are analyzed.