Accurate calculations of U(1) lattice gauge theory

Abstract

We apply the powerful coupled cluster method (CCM) to the U(1) lattice gauge model in 2+1 dimensions, using as a reference state for our analysis a self-consistent “mean-field” state which includes a large class of one-body correlations. We consider up to local two-body correlations and obtain results which are on a par with those from the best alternative techniques. Our results strongly indicate that the ground state of the U(1) system in 2+1 dimensions is rather weakly correlated.