Canonical Light-Cone Commutators

We study the canonical structure of current commutators on the light cone, as embodied in Kogut and Soper's formulation of quantum electrodynamics in the infinite-momentum frame. These commutators incorporate dynamical information far beyond that contained in conventional equal-time commutation relations. An analog of the Bjorken-Johnson-Low limit is developed for calculating matrix elements of light-cone commutators from conventional time-ordered products. Some apparently new sum rules for electroproduction are obtained. They relate Fourier transforms of structure functions to bilocal products of operators. We suggest possible directions for constructing phenomenological light-cone commutators in hadronic physics. These commutators can be used to describe entire Regge trajectories, and might find application to electroproduction and neutrino-induced production experiments.