The projector Monte-Carlo method - a trial of a new technique to analyze lattice gauge theories with fermions in the Hamiltonian formulation

All presently known methods for the Monte-Carlo simulation of lattice gauge theories with dynamical fermions are rather slow and time consuming. Therefore, the development and test of new Monte-Carlo methods for fermions is of great interest. The present paper presents a first application of the projector Monte-Carlo method to a lattice gauge theory with fermions, the massive Schwinger model, that is QED in 1 + 1 dimensions. Expectation values calculated for the average energy and the fermion condensate agree with results obtained before with the local Hamiltonian Monte-Carlo method. In contrast to the latter method, the projector Monte-Carlo method should also be applicable to gauge theories in 2 + 1 and 3 + 1 dimensions. (author)