S. Pinsky et U. Trittmann, Antiperiodic boundary conditions in supersymmetric discrete light cone quantization - art. no. 087701, PHYS REV D, 6208(8), 2000, pp. 7701
It is of considerable importance to have a numerical method for solving sup
ersymmetric theories that can support a non-zero central charge. The centra
l charge in supersymmetric theories is in general a boundary integral and t
herefore vanishes when one uses periodic boundary conditions. One is theref
ore prevented from studying BPS states in the standard supersymmetric formu
lation of DLCQ (SDLCQ). We present a novel formulation of SDLCQ where the f
ields satisfy antiperiodic boundary conditions. The Hamiltonian is written
as the anti-commutator of two charges, as in SDLCQ. The antiperiodic SDLCQ
we consider breaks supersymmetry at finite resolution, but requires no reno
rmalization and becomes supersymmetric in the continuum limit. In principle
, this method could be used to study BPS states. However, we find its conve
rgence to be disappointingly slow.