Progress in lattice algorithms

The development of Monte Carlo algorithms for generating gauge field configurations with dynamical fermions and methods for extracting the most information from ensembles are summarised.Comment: Lattice2001(plenary) 9 pages, 4 figures. Uses espcrc2.st

Dynamical fermion simulations using Luescher's local bosonic action algorithm

The two-flavour Schwinger model is used to test the local boson action algorithm of M Luescher. The autocorrelation time is found to rise linearly with the number of auxiliary boson fields. An extension to the algorithm is proposed which exactly reproduces the full dynamical partition function for any number of boson fields.Comment: 3 pages - uuencoded PostScript. Contribution to proceedings of Lattice '9

Simulating the scalar glueball on the lattice

Techniques for efficient computation of the scalar glueball mass on the lattice are described. Directions and physics goals of proposed future calculations will be outlined.Comment: 9 pages, 3 figures, submitted to the proceedings of the SUNYIT Scalar Mesons workshop (May 2003

Analytic Smearing of SU(3) Link Variables in Lattice QCD

An analytic method of smearing link variables in lattice QCD is proposed and tested. The differentiability of the smearing scheme with respect to the link variables permits the use of modern Monte Carlo updating methods based on molecular dynamics evolution for gauge-field actions constructed using such smeared links. In examining the smeared mean plaquette and the static quark-antiquark potential, no degradation in effectiveness is observed as compared to link smearing methods currently in use, although an increased sensitivity to the smearing parameter is found.Comment: 8 pages, 4 figures, uses RevTe

Polynomial Filtered HMC -- an algorithm for lattice QCD with dynamical quarks

Polynomial approximations to the inverse of the fermion matrix are used to filter the dynamics of the upper energy scales in HMC simulations. The use of a multiple time-scale integration scheme allows the filtered pseudofermions to be evolved using a coarse step size. We introduce a novel generalisation of the nested leapfrog which allows for far greater flexibility in the choice of time scales. We observe a reduction in the computational expense of the molecular dynamics integration of between 3--5 which improves as the quark mass decreases.Comment: 10 pages, 7 figure