Mb. Paranjape et R. Ross, INSTANTONS AND THE GROUND-STATE OF THE MASSIVE SCHWINGER MODEL, Physical review. D. Particles and fields, 48(8), 1993, pp. 3891-3900
We study the massive Schwinger model, quantum electrodynamics of massi
ve, Dirac fermions, in 1 + 1 dimensions, with space compactified to a
circle. In the limit that transitions to fermion-antifermion pairs can
be neglected, we study the full ground state. We focus on the effect
of instantons which mediate tunneling transitions in the induced poten
tial for the dynamical degree of freedom in the gauge field. We calcul
ate the nonperturbative contributions to the ground state energy.