Irreducible representations of the CPT groups in QED

Abstract

We construct the inequivalent irreducible representations (IIR's) of the CPT groups of the Dirac field operator \hat{\psi} and the electromagnetic quantum potential \hat{A}_\mu. The results are valid both for free and interacting (QED) fields. Also, and for the sake of completeness, we construct the IIR's of the CPT group of the Dirac equation.