A numerical experiment in DLCQ: microcausality, continuum limit and all that

Issues related with microcausality violation and continuum limit in the con text of (1 + 1) dimensional scalar field theory in discretized light-cone q uantization (DLCQ) are addressed in parallel with discretized equal time qu antization (DETQ) and the fact that Lorentz invariance and microcausality a re restored if one can take the continuum limit properly is emphasized. In the free case, it is shown with numerical evidence that the continuum resul ts can be reproduced from DLCQ results for the Pauli-Jordan function and th e real part of Feynman propagator. The contributions coming from k(+) near zero region in these cases are found to be very small. In the interacting c ase, aspects related to the continuum limit of DLCQ results in perturbation theory in momentum space are discussed. (C) 2000 Published by Elsevier Sci ence B.V. All rights reserved.