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Related papers: Adaptive Multigrid Algorithm for Lattice QCD

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We present a new multigrid solver that is suitable for the Dirac operator in the presence of disordered gauge fields. The key behind the success of the algorithm is an adaptive projection onto the coarse grids that preserves the near null…

High Energy Physics - Lattice · Physics 2008-11-26 J. Brannick , R. C. Brower , M. A. Clark , J. C. Osborn , C. Rebbi

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…

High Energy Physics - Lattice · Physics 2010-12-02 R. Babich , J. Brannick , R. C. Brower , M. A. Clark , T. A. Manteuffel , S. F. McCormick , J. C. Osborn , C. Rebbi

We report on the first successful QCD multigrid algorithm which demonstrates constant convergence rates independent of quark mass and lattice volume for the Wilson Dirac operator. The new ingredient is the adaptive method for constructing…

High Energy Physics - Lattice · Physics 2010-04-15 Ronald Babich , James Brannick , Richard C. Brower , Michael A. Clark , Saul D. Cohen , James C. Osborn , Claudio Rebbi

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…

High Energy Physics - Lattice · Physics 2010-04-05 M. A. Clark , J. Brannick , R. C. Brower , S. F. McCormick , T. A. Manteuffel , J. C. Osborn , C. Rebbi

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 large system sizes and physically interesting parameter…

High Energy Physics - Lattice · Physics 2014-04-29 Andreas Frommer , Karsten Kahl , Stefan Krieg , Björn Leder , Matthias Rottmann

Critical slowing down for the Krylov Dirac solver presents a major obstacle to further advances in lattice field theory as it approaches the continuum solution. We propose a new multi-grid approach for chiral fermions, applicable to both…

High Energy Physics - Lattice · Physics 2020-12-30 Richard C. Brower , M. A. Clark , Dean Howarth , Evan S. Weinberg

Adaptive multi-grid methods have proven very successful in dealing with critical slow down for the Wilson-Dirac solver in lattice gauge theory. Multi-grid algorithms developed for Staggered fermions using the K\"ahler-Dirac…

High Energy Physics - Lattice · Physics 2023-04-28 Venkitesh Ayyar , Richard Brower , M. A. Clark , Mathias Wagner , Evan Weinberg

The construction of multigrid operators for disordered linear lattice operators, in particular the fermion matrix in lattice gauge theories, by means of algebraic multigrid and block LU decomposition is discussed. In this formalism, the…

High Energy Physics - Lattice · Physics 2016-09-01 Christoph Best

Multigrid methods were invented for the solution of discretized partial differential equations in ordered systems. The slowness of traditional algorithms is overcome by updates on various length scales. In this article we discuss…

High Energy Physics - Lattice · Physics 2011-04-15 Thomas Kalkreuter

We describe an adaptive multigrid algorithm for solving inverses of the domain-wall fermion operator. Our multigrid algorithm uses an adaptive projection of near-null vectors of the domain-wall operator onto coarser four-dimensional…

High Energy Physics - Lattice · Physics 2012-05-15 Saul D. Cohen , R. C. Brower , M. A. Clark , J. C. Osborn

Critical slowing down in Krylov methods for the Dirac operator presents a major obstacle to further advances in lattice field theory as it approaches the continuum solution. Here we formulate a multi-grid algorithm for the Kogut-Susskind…

High Energy Physics - Lattice · Physics 2018-07-04 Richard C. Brower , M. A. Clark , Alexei Strelchenko , Evan Weinberg

We present an adaptive multigrid Dirac solver developed for Wilson clover fermions which offers order-of-magnitude reductions in solution time compared to conventional Krylov solvers. The solver incorporates even-odd preconditioning and…

High Energy Physics - Lattice · Physics 2011-05-25 J. C. Osborn , R. Babich , J. Brannick , R. C. Brower , M. A. Clark , S. D. Cohen , C. Rebbi

Lattice QCD solvers encounter critical slowing down for fine lattice spacings and small quark mass. Traditional matrix eigenvalue deflation is one approach to mitigating this problem. However, to improve scaling we study the effects of…

High Energy Physics - Lattice · Physics 2020-02-26 Travis Whyte , Walter Wilcox , Ronald B. Morgan

The multigrid methodology is reviewed. By integrating numerical processes at all scales of a problem, it seeks to perform various computational tasks at a cost that rises as slowly as possible as a function of $n$, the number of degrees of…

High Energy Physics - Lattice · Physics 2009-10-22 Achi Brandt

Numerical simulations of quantum chromodynamics (QCD) on a lattice require the frequent solution of linear systems of equations with large, sparse and typically ill-conditioned matrices. Algebraic multigrid methods are meanwhile the…

Numerical Analysis · Mathematics 2023-03-28 Jesus Espinoza-Valverde , Andreas Frommer , Gustavo Ramirez-Hidalgo , Matthias Rottmann

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 opposed to other discretizations it preserves the important…

High Energy Physics - Lattice · Physics 2014-10-28 James Brannick , Andreas Frommer , Karsten Kahl , Björn Leder , Matthias Rottmann , Artur Strebel

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 results of the extension of the two-level DD-\alpha AMG method to…

High Energy Physics - Lattice · Physics 2013-07-24 A. Frommer , K. Kahl , S. Krieg , B. Leder , M. Rottmann

Linear systems arise in generating samples and in calculating observables in lattice quantum chromodynamics~(QCD). Solving the Hermitian positive definite systems, which are sparse but ill-conditioned, involves using iterative methods, such…

High Energy Physics - Lattice · Physics 2025-09-15 Yixuan Sun , Srinivas Eswar , Yin Lin , William Detmold , Phiala Shanahan , Xiaoye Li , Yang Liu , Prasanna Balaprakash

In order to develop fast inversion algorithms we have used overlap solvers in two dimensions. Lattice QED theory with U(1) group symmetry in two dimensional space-times dimensions has always been a testing ground for algorithms. By the…

High Energy Physics - Lattice · Physics 2014-06-25 Dafina Xhako , Artan Boriçi

Unfitted finite element methods have emerged as a popular alternative to classical finite element methods for the solution of partial differential equations and allow modeling arbitrary geometries without the need for a boundary-conforming…

Numerical Analysis · Mathematics 2021-03-19 S. Saberi , G. Meschke , A. Vogel
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