RENORMALIZABILITY PROOF FOR QED BASED ON FLOW EQUATIONS

We prove the perturbative renormalizability of Euclidean QED(4) using flow equations, i.e. with the aid of the Wilson renormalization group adapted to perturbation theory. As compared to Phi(4)(4) the additiona l difficulty to overcome is that the regularization violates gauge inv ariance. We prove that there exists a class of renormalization conditi ons such that the renormalized Green functions satisfy the QED Ward id entities and such that they are infrared finite at nonexceptional mome nta. We give bounds on the singular behaviour at exceptional momenta ( due to the massless photon) and comment on the adaptation to the case when the fermions are also massless.