ISING-MODEL MONTE-CARLO SIMULATIONS - DENSITY OF STATES AND MASS GAP

We have performed Monte Carlo simulations for the three-dimensional Ising model. Using histogram techniques, we calculate the density of states on L3 block lattices up to size L=14. Statistical jackknife methods are employed to perform a thorough error analysis. We obtain high-precision estimates for the leading zeros of the partition function, which, using finite-size scaling, translate into =0.6285 0.0019. Along a different line of approach following recent work in lattice-gauge theories, we accurately determine the mass gap m=1/ ( correlation length) for cylindrical L2Lz lattices (with Lz=256 and L up to 12). The finite-size-scaling analysis of the mass-gap data leads to =0.6321 0.0019. © 1990 The American Physical Society.