Computational Methods for UV-Suppressed Fermions

Lattice fermions with suppressed high momentum modes solve the ultraviolet slowing down problem in lattice QCD. This paper describes a stochastic evaluation of the effective action of such fermions. The method is a based on the Lanczos algorithm and it is shown to have the same complexity as in the case of standard fermions.Comment: 10 pages, 1 figur

Truncated Overlap Fermions

In this talk I propose a new computational scheme with overlap fermions and a fast algorithm to invert the corresponding Dirac operator.Comment: LATTICE99(algorithms

Global Monte Carlo for fermions using ordered statistics

In this talk I discuss a new possibility for stochastic representation of the fe rmion determinant. The method can be used for global Monte Carlo fermion algorit hms and is tested in the case of the Schwinger model.Comment: 3 pages, Lattice2003 (Machines I

Scaling in SU(3) theory with a MCRG improved lattice action

We test various improved gauge actions which are made of linear combinations of Wilson loops. We observe the restoration of rotational symmetry in the static interquark potential already on coarse lattices as small as 6^3x12. Furthermore, we study scaling and asymptotic scaling of the string tension with a MCRG-improved action on 12^3x24 lattices. Preliminary results show that scaling sets in at a ~ 0.3 fm.Comment: 3 pages, 4 figures, contribution at Lattice '97, Edinburg

Fractional Inversion in Krylov Space

The fractional inverse $M^{-\gamma}$ (real $\gamma >0$) of a matrix $M$ is expanded in a series of Gegenbauer polynomials. If the spectrum of $M$ is confined to an ellipse not including the origin, convergence is exponential, with the same rate as for Chebyshev inversion. The approximants can be improved recursively and lead to an iterative solver for $M^\gamma x = b$ in Krylov space. In case of $\gamma = 1/2$, the expansion is in terms of Legendre polynomials, and rigorous bounds for the truncation error are derived.Comment: Contribution to LAT97 proceedings, 3 page

Variants of L\"uscher's fermion algorithm

We study improved variants of L\"uscher's algorithm, including the cases of staggered fermions and finite density.Comment: 4 uuencoded PostScript pages, contribution to LAT95 (fig.1 removed to conserve space; available upon request

Exact Local Bosonic Algorithm for Dynamical Quarks

We present an exact local bosonic algorithm for the simulation of dynamical fermions in lattice QCD. We show that this algorithm is a viable alternative to the Hybrid Monte Carlo algorithm.Comment: 3 pages, 1 PostScript figure; Talk presented at LATTICE96(algorithms

Accurate hadron spectroscopy on blocked configurations by tadpole-renormalized, clover-improved Wilson quark action

We compare the quenched hadron spectrum on blocked and unblocked lattices for the Wilson quark action, the clover action and the tadpole-improved clover action. The latter gives a spectrum markedly closer to the original one, even though the cutoff is 1/a ~ 500 Mev.Comment: 3 pages (4 included figures), contribution to Lattice 94 conference, uuencoded compressed postscript fil