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Related papers: Solving the Dirac equation on QPACE

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I review recent machine trends and algorithmic developments for dynamical lattice QCD simulations with the HMC algorithm for Wilson-type fermions. The topics include the trend toward multi-core processors and general purpose GPU (GPGPU)…

High Energy Physics - Lattice · Physics 2010-01-21 Ken-Ichi Ishikawa

A parallelizable SSOR preconditioning scheme for Krylov subspace iterative solvers in lattice QCD applications involving Wilson fermions is presented. In actual Hybrid Monte Carlo and quark propagator calculations it helps to reduce the…

High Energy Physics - Lattice · Physics 2009-10-28 S. Fischer , A. Frommer , U. Glaessner , S. Guesken , H. Hoeber , Th. Lippert , G. Ritzenhoefer , K. Schilling , G. Siegert , A. Spitz

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 overlapping Schwarz decomposition algorithm for constrained quadratic programs (QPs). Schwarz algorithms have been traditionally used to solve linear algebra systems arising from partial differential equations, but we have…

Optimization and Control · Mathematics 2021-02-17 Sungho Shin , Mihai Anitescu , Victor M. Zavala

We present a parallel solver for numerical constraint satisfaction problems (NCSPs) that can scale on a number of cores. Our proposed method runs worker solvers on the available cores and simultaneously the workers cooperate for the search…

Artificial Intelligence · Computer Science 2014-11-07 Daisuke Ishii , Kazuki Yoshizoe , Toyotaro Suzumura

The finite cell method is a highly flexible discretization technique for numerical analysis on domains with complex geometries. By using a non-boundary conforming computational domain that can be easily meshed, automatized computations on a…

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

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

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 a scalable parallel solver for numerical constraint satisfaction problems (NCSPs). Our parallelization scheme consists of homogeneous worker solvers, each of which runs on an available core and communicates with others via the…

Distributed, Parallel, and Cluster Computing · Computer Science 2015-05-19 Daisuke Ishii , Kazuki Yoshizoe , Toyotaro Suzumura

The action of the overlap-Dirac operator on a vector is typically implemented indirectly through a multi-shift conjugate gradient solver. The compute-time required depends upon the condition number, $\kappa$, of the matrix that is used as…

High Energy Physics - Lattice · Physics 2010-03-04 W. Kamleh , D. B. Leinweber , A. G. Williams , J. B. Zhang

Lattice QCD calculations require significant computational effort, with the dominant fraction of resources typically spent in the numerical inversion of the Dirac operator. One of the simplest methods to solve such large and sparse linear…

High Energy Physics - Lattice · Physics 2021-12-01 Salvatore Cali , William Detmold , Grzegorz Korcyl , Piotr Korcyl , Phiala Shanahan

In this work, we propose an adaptive geometric multigrid method for the solution of large-scale finite cell flow problems. The finite cell method seeks to circumvent the need for a boundary-conforming mesh through the embedding of the…

Numerical Analysis · Mathematics 2026-01-21 M. Saberi , A. Vogel

An overview is given of the QCDOC architecture, a massively parallel and highly scalable computer optimized for lattice QCD using system-on-a-chip technology. The heart of a single node is the PowerPC-based QCDOC ASIC, developed in…

High Energy Physics - Lattice · Physics 2007-05-23 P. A. Boyle , C. Jung , T. Wettig

Computational speed and global optimality are key needs for practical algorithms for the optimal power flow problem. Two convex relaxations offer a favorable trade-off between the standard second-order cone and the standard semidefinite…

Optimization and Control · Mathematics 2021-12-23 Christian Bingane , Miguel F. Anjos , Sébastien Le Digabel

In this work we propose an efficient parallelization of multiple-precision Taylor series method with variable stepsize and fixed order. For given level of accuracy the optimal variable stepsize determines higher order of the method than in…

Numerical Analysis · Mathematics 2021-10-20 I. Hristov , R. Hristova , S. Dimova , P. Armyanov , N. Shegunov , I. Puzynin , T. Puzynina , Z. Sharipov , Z. Tukhliev

Graphical Processing Units (GPUs) are more and more frequently used for lattice QCD calculations. Lattice studies often require computing the quark propagators for several masses. These systems can be solved using multi-shift inverters but…

High Energy Physics - Lattice · Physics 2015-05-27 A. Alexandru , C. Pelissier , B. Gamari , F. Lee

We show that using the multisplitting algorithm as a preconditioner for conjugate gradient inversion of the domain wall fermion Dirac operator could effectively reduce the inter-node communication cost, at the expense of performing more…

High Energy Physics - Lattice · Physics 2018-11-22 Jiqun Tu

Elliptic partial differential equations must be solved numerically for many problems in numerical relativity, such as initial data for every simulation of merging black holes and neutron stars. Existing elliptic solvers can take multiple…

We present a non-iterative solver based on the Schur complement method for sparse linear systems of special form which appear in Quantum Monte-Carlo (QMC) simulations of strongly interacting fermions on the lattice. While the number of…

Strongly Correlated Electrons · Physics 2019-01-30 Maksim Ulybyshev , Nils Kintscher , Karsten Kahl , Pavel Buividovich