  Critical properties of the compact three-dimensional U(1) lattice gauge
theory are explored at finite temperatures on an asymmetric lattice. For
vanishing value of the spatial gauge coupling one obtains an effective
two-dimensional spin model which describes the interaction between Polyakov
loops. We study numerically the effective spin model for N_t=1,4,8 on lattices
with spatial extension ranging from L=64 to L=256. Our results indicate that
the finite-temperature U(1) lattice gauge theory belongs to the universality
class of the two-dimensional XY model, thus supporting the Svetitsky-Yaffe
conjecture.
