The dynamics of the electromagnetic vector potential is analyzed in full detail in view
of the principle of general local covariance of Brunetti, Fredenhagen and
Verch. Exploiting this result, the relative Cauchy evolution for the vector
potential is introduced and its relation with the energy-momentum tensor is
established, extending the well known results for Klein–Gordon and Dirac
fields.
Keywords
quantum field theory on curved spacetimes, Maxwell
equation, general local covariance, relative Cauchy
evolution
