CRITICAL-BEHAVIOR IN PURE COMPACT U(1) GAUGE-THEORY ON TOROIDAL LATTICES

We report results of a high-statistics Monte Carlo simulation of the p hase transition in compact U(1) lattice gauge theory with Wilson actio n on a hypercubic lattice with periodic boundary conditions. By a care ful analysis of the histograms of the plaquette energy distribution, w e can measure gaps with sufficient accuracy on lattice sizes ranging f rom 4(4) to 16(4). We find that all data points can be successfully re produced by the two-parameter ansatz Delta e(L) = Delta e(infinity) all with a non-zero latent heat in the infinite volume limit. On the o ther hand we confirm that the pseudo-critical temperatures scale with a critical exponent nu = 0.326(8) different from the first-order predi ction nu = 0.25. We also check the scaling of the maximum of the speci fic heat with a critical exponent a consistent with the hyperscaling r elation. (C) 1997 Elsevier Science B.V.