The long range properties of the compact U(1) lattice gauge theory with the multi-level algorithm

The 4D compact U(1) lattice gauge theory (LGT) in the confinement phase is studied with the multi-level algorithm. The static potential, force and flux-tube profile between two static charges are precisely measured from correlation functions involving the Polyakov loop. Universality of the coefficient of the 1/r correction to the static potential, known as the Luescher term, and the transversal width of the flux-tube profile are investigated.