Time evolution in general gauge theories on inner product spaces Original Research Article

After a study of BRST singlets in corresponding reparametrization invariant formulations it is shown that the time evolution of BRST singlets in a BRST quantization of general gauge theories on inner product spaces may be chosen to be determined by a Schrödinger equation. The appropriate Hamiltonian for this is a particular truncated Hamiltonian of the original one. This Hamiltonian leads also to a particular BRST invariant gauge fixed theory. For electromagnetism one gets in this way the gauge fixed theory in the Feynman gauge. This Lagrangian is also shown to be coBRST invariant.