1,862 research outputs found
Multigrid for propagators of staggered fermions in four-dimensional gauge fields
Multigrid (MG) methods for the computation of propagators of staggered
fermions in non-Abelian gauge fields are discussed. MG could work in principle
in arbitrarily disordered systems. The practical variational MG methods tested
so far with a ``Laplacian choice'' for the restriction operator are not
competitive with the conjugate gradient algorithm on lattices up to .
Numerical results are presented for propagators in gauge fields.Comment: 4 pages, 3 figures (one LaTeX-figure, two figures appended as
encapsulated ps files); Contribution to LATTICE '92, requires espcrc2.st
Dynamical Scaling from Multi-Scale Measurements
We present a new measure of the Dynamical Critical behavior: the "Multi-scale
Dynamical Exponent (MDE)"Comment: 9 pages,Latex, Request figures from [email protected]
Idealized Multigrid Algorithm for Staggered Fermions
An idealized multigrid algorithm for the computation of propagators of
staggered fermions is investigated.
Exemplified in four-dimensional gauge fields, it is shown that the
idealized algorithm preserves criticality under coarsening.
The same is not true when the coarse grid operator is defined by the Galerkin
prescription.
Relaxation times in computations of propagators are small, and critical
slowing is strongly reduced (or eliminated) in the idealized algorithm.
Unfortunately, this algorithm is not practical for production runs, but the
investigations presented here answer important questions of principle.Comment: 11 pages, no figures, DESY 93-046; can be formatted with plain LaTeX
article styl
Some Comments on Multigrid Methods for Computing Propagators
I make three conceptual points regarding multigrid methods for computing
propagators in lattice gauge theory: 1) The class of operators handled by the
algorithm must be stable under coarsening. 2) Problems related by symmetry
should have solution methods related by symmetry. 3) It is crucial to
distinguish the vector space from its dual space . All the existing
algorithms violate one or more of these principles.Comment: 16 pages, LaTeX plus subeqnarray.sty (included at end),
NYU-TH-93/07/0
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