AUTOCORRELATION IN UPDATING PURE SU(3) LATTICE GAUGE-THEORY BY THE USE OF OVERRELAXED ALGORITHMS

We measure the sweep-to-sweep autocorrelations of blocked loops below and above th, deconfinement transition for SU(3) on a 16(4) lattice using 20000-140000 Monte-Carlo updating sweeps. A divergence of the autocorrelation time toward the critical beta is seen at high blocking levels. The peak is near beta = 6.33 where we observe 440 +/- 210 for the autocorrelation time of 1 x 1 Wilson loop on 2(4) blocked lattice. The mixing of 7 Brown-Woch overrelaxation steps followed by one pseudo-heat-bath step appears optimal to reduce the autocorrelation time below the critical beta. Above the critical beta, however, no clear difference between these two algorithms can be seen and the system decorrelates rather fast.