  We study analytically and numerically the three-dimensional U(1) lattice
gauge theory at finite temperature in the dual formulation. For an appropriate
disorder operator, we obtain the renormalization group equations describing the
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. Furthermore, we perform numerical simulations of the model for $N_t = 1,
2, 4, 8$ and compute, by a cluster algorithm, the dual correlation functions
and the corresponding second moment correlation length. In this way we locate
the position of the critical point and calculate critical indices.
