Canonical formulation of quantum field theory on the Light Front (LF) is reviewed. The problem of constructing the LF Hamiltonian which gives the theory equivalent to original Lorentz and gauge invariant one is considered. We describe possible ways of solving this problem: (a) the limiting transition from the equal-time Hamiltonian in a fast moving Lorentz frame to LF Hamiltonian, (b) the direct comparison of LF perturbation theory in coupling constant and usual Lorentz-covariant Feynman perturbation theory. The results of the application of method (b) to QED-1+1 and QCD-3+1 are given. Gauge invariant regularization of LF Hamiltonian via introducing a lattice in transverse coordinates and imposing periodic boundary conditions in LF coordinate x^- for gauge fields on the interval |x^-| smaller than L is also considered.
- Pub Date:
- April 2004
- High Energy Physics - Theory
- LaTeX 2.09, 48 pages. The paper is written for editorial collection "Progress in Field Theory Research", Nova Science Publishers, New York. New improved expression for the effective LF Hamiltonian of QED(1+1) was added