arXiv subjects

S. F. McCormick

Publications and source records attributed to S. F. McCormick.

2 recordsLinked to original sources

arXiv2010

Adaptive multigrid algorithm for the lattice Wilson-Dirac operator

We present an adaptive multigrid solver for application to the non-Hermitian Wilson-Dirac system of QCD. The key components leading to the success of our proposed algorithm are the use of an adaptive projection onto coarse grids that preserves the near null space of the system matrix together with a simplified form of the correction based on the so-called gamma_5-Hermitian symmetry of the Dirac operator. We demonstrate that the algorithm nearly eliminates critical slowing down in the chiral limit and that it has weak dependence on the lattice volume.

hep-lat↗

arXiv2010

The removal of critical slowing down

We present promising initial results of our adaptive multigrid solver developed for application directly to the non-Hermitian Wilson-Dirac system in 4 dimensions, as opposed to the solver developed in [1] for the corresponding normal equations. The key behind the success of this algorithm is the use of an adaptive projection onto coarse grids that preserves the near null space of the system matrix. We demonstrate that the resulting algorithm has weak dependence on the gauge coupling and exhibits extremely mild critical slowing down in the chiral limit.

hep-lat↗