Realistic regularization of the QED Green functions

Generalizing the 't Hooft and Veltman method of unitary regulators, we demonstrate for the first time the existence of local, Lorentz-invariant, physically motivated Lagrangians of quantum-electrodynamic phenomena such that: (i) Feynman diagrams are finite and equal the diagrams of QED but with regularized propagators. (ii) N-point Green functions are C-, P-, and T-invariant up to a phase factor, Lorentz-invariant and causal. (iii) No auxiliary particles or parameters are introduced.