Twist free energy and critical behavior of 3D U(1) LGT at finite temperature

Abstract: The twist free energy is computed in the Villain formulation of the 3D U(1) lattice gauge theory at finite temperature. This enables us to obtain renormalization group equations describing a critical behavior of the model in the vicinity of the deconfinement phase transition. These equations are used to check the validity of the Svetitsky-Yaffe conjecture regarding the critical behavior of the lattice U(1) model. In particular, we calculate the two-point correlation function of the Polyakov loops and determine some critical indices.