74 citations · 156 across the 28 of their papers we have counts for
10 papers · 1 filter
A multigrid accelerated eigensolver for the Hermitian Wilson-Dirac operator in lattice QCD
Andreas Frommer, Karsten Kahl, Francesco Knechtli +3
Eigenvalues of the Hermitian Wilson-Dirac operator are of special interest in several lattice QCD simulations, e.g., for noise reduction when evaluating all-to-all propagators. In…
Adaptive Aggregation-based Domain Decomposition Multigrid for Twisted Mass Fermions
Constantia Alexandrou, Simone Bacchio, Jacob Finkenrath +3
The Adaptive Aggregation-based Domain Decomposition Multigrid method (arXiv:1303.1377) is extended for two degenerate flavors of twisted mass fermions. By fine-tuning the parameter…
DDalphaAMG for Twisted Mass Fermions
Simone Bacchio, Costantia Alexandrou, Jacob Finkenrath +3
We present the Adaptive Aggregation-based Domain Decomposition Multigrid method extended to the twisted mass fermion discretization action. We show comparisons of results as a func…
(Approximate) Low-Mode Averaging with a new Multigrid Eigensolver
Gunnar Bali, Sara Collins, Andreas Frommer +5
We present a multigrid based eigensolver for computing low-modes of the Hermitian Wilson Dirac operator. For the non-Hermitian case multigrid methods have already replaced conventi…
Multigrid Preconditioning for the Overlap Operator in Lattice QCD
James Brannick, Andreas Frommer, Karsten Kahl +3
The overlap operator is a lattice discretization of the Dirac operator of quantum chromodynamics, the fundamental physical theory of the strong interaction between the quarks. As o…
An adaptive aggregation based domain decomposition multilevel method for the lattice wilson dirac operator: multilevel results
A. Frommer, K. Kahl, S. Krieg +2
In lattice QCD computations a substantial amount of work is spent in solving linear systems arising in Wilson's discretization of the Dirac equations. We show first numerical resul…
Adaptive Aggregation Based Domain Decomposition Multigrid for the Lattice Wilson Dirac Operator
Andreas Frommer, Karsten Kahl, Stefan Krieg +2
In lattice QCD computations a substantial amount of work is spent in solving discretized versions of the Dirac equation. Conventional Krylov solvers show critical slowing down for…
2-norm error bounds and estimates for Lanczos approximations to linear systems and rational matrix functions
A. Frommer, K. Kahl, Th. Lippert +1
The Lanczos process constructs a sequence of orthonormal vectors v_m spanning a nested sequence of Krylov subspaces generated by a hermitian matrix A and some starting vector b. In…
Aggregation-based Multilevel Methods for Lattice QCD
Andreas Frommer, Karsten Kahl, Stefan Krieg +2
In Lattice QCD computations a substantial amount of work is spent in solving the Dirac equation. In the recent past it has been observed that conventional Krylov solvers tend to cr…
Error Bounds for the Sign Function
Andreas Frommer, Karsten Kahl, Thomas Lippert +1
The Overlap operator fulfills the Ginsparg-Wilson relation exactly and therefore represents an optimal discretization of the QCD Dirac operator with respect to chiral symmetry. Whe…