Lattice Schwinger model with interpolated gauge fields.

Abstract

We analyze the Schwinger model on an infinite lattice using the continuum definition of the fermion determinant and a linear interpolation of the lattice gauge fields. The possible class of interpolations for the gauge fields, compatible with gauge invariance, is discussed. The effective action for the lattice gauge field is computed for the Wilson formulation as well as for noncompact lattice gauge fields. For the noncompact formulation we prove that the model has a critical point with diverging correlation length at zero gauge coupling e. We compute the chiral condensate for e\ensuremath{\gtrsim}0 and compare the result to the N-flavor continuum Schwinger model. This indicates that there is only one flavor of fermions with the same chiral properties as in the continuum model, already before the continuum limit is performed. We discuss how operators have to be renormalized in the continuum limit to obtain the continuum Schwinger model. \textcopyright{} 1996 The American Physical Society.