  Fundamental problems of quantum field theory related to the representation
problem of canonical commutation relations are discussed within a gauge field
version of a van Hove-type model. The Coulomb field generated by a static
charge distribution is described as a formal superposition of time-like
pseudo-photons in Fock space with a Krein structure. In this context, a
generalization of operator gauge transformations is introduced to generate
coherent states of abelian gauge fields interacting with a charged background.
