Consistent perturbative light-front formulation of quantum electrodynamics

Abstract

A new light-front formulation of Q.E.D. is developed, within the framework of standard perturbation theory, in which $x^+$ plays the role of the evolution parameter and the gauge choice is $A_+=0$ (light-front "temporal" gauge). It is shown that this formulation leads to the Mandelstam-Leibbrandt causal prescription for the non-covariant singularities in the photon propagator. Furthermore, it is proved that the dimensionally regularized one loop off-shell amplitudes exactly coincide with the correct ones, as computed within the standard approach using ordinary space-time coordinates.