On the Schwinger Model on Riemann Surfaces

In this paper, the massless Schwinger model or two dimensional quantum electrodynamics is exactly solved on a Riemann surface. The partition function and the generating functional of the correlation functions involving the fermionic currents are explicitly derived using a method of quantization valid for any abelian gauge field theory and explained in the recent references [F. Ferrari, {\it Class. Quantum Grav.} {\bf 10} (1993), 1065], [F. Ferrari, hep-th 9310024]. In this sense, the Schwinger model is one of the few examples of interacting and nontopological field theories that are possible to quantize on a Riemann surface. It is also shown here that the Schwinger model is equivalent to a nonlocal integrable model which represents a generalization of the Thirring model. Apart from the possible applications in string theory and integrable models, we hope that this result can be also useful in the study of quantum field theories in curved space-times.