INFRARED BEHAVIOR OF THE GLUON PROPAGATOR IN LATTICE LANDAU GAUGE

We evaluate numerically the four-momentum-space gluon propagator in la ttice Landau gauge, for pure SU(2) lattice gauge theory with periodic boundary conditions. Simulations are done in the strong-coupling regim e, namely at beta = 0, 0.8, 1.2 and 1.6, and for lattice sizes up to 3 0(4), 16(4), 20(4) and 24(4) respectively. In the Limit of large latti ce volume, we observe in all cases a gluon propagator decreasing as th e momentum goes to zero. This counter-intuitive result has a straightf orward interpretation as resulting from the proximity of the so-called first Gribov horizon in infrared directions. (C) 1998 Published by El sevier Science B.V.