The geometric Schwinger model on the lattice

The geometric Schwinger model has an interesting non-perturbative structure related to topological index theorems. This is analyzed on the euclidean lattice with staggered fermions. Using the hybrid Monte Carlo simulation we calculate the exponential decay of the field strength correlation and the screening of the heavy quark potential including finite volume effects. For both cases the transition from strong to weak coupling behaviour is studied. These calculations are complemented by an unquenched strong coupling expansion. Furthermore, we characterize fermion bilinears by their lattice symmetry properties. The Monte Carlo results on their correlation functions can then be discussed under the aspects of the anomalous U(1)_A symmetry breaking. The toron part of the effective action is measured too. (orig.)Available from TIB Hannover: RA 2999(93-181) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman