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Related papers: A Preconditioner for Improved Fermion Actions

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We construct a locally-lexicographic SSOR preconditioner to accelerate the parallel iterative solution of linear systems of equations for two improved discretizations of lattice fermions: the Sheikholeslami-Wohlert scheme where a…

High Energy Physics - Lattice · Physics 2009-10-31 W. Bietenholz , N. Eicker , A. Frommer , Th. Lippert , B. Medeke , K. Schilling , G. Weuffen

We generalize local lexicographic SSOR preconditioning for the Sheikholeslami-Wohlert improved Wilson fermion action and the truncated perfect free fermion action. In our test implementation we achieve performance gains as known from SSOR…

High Energy Physics - Lattice · Physics 2009-10-30 N. Eicker , W. Bietenholz , A. Frommer , H. Hoeber , Th. Lippert , K. Schilling

We present a parallelizable SSOR preconditioning scheme for Krylov subspace iterative solvers which proves to be efficient in lattice QCD applications involving Wilson fermions. Our preconditioner is based on a locally lexicographic…

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

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

SU(2) gauge theory with two fermions transforming under the adjoint representation may appear conformal or almost conformal in the infrared, and is one of the candidate theories for building models for technicolor. Early lattice Monte Carlo…

High Energy Physics - Lattice · Physics 2015-05-20 Tuomas Karavirta , Anne Mykkanen , Jarno Rantaharju , Kari Rummukainen , Kimmo Tuominen

We discuss the application of hybrid over-relaxation, even-odd preconditioning and a modified local updating procedure to the local bosonic fermion algorithm. Studies on autocorrelation times and the tuning of the parameters of the…

High Energy Physics - Lattice · Physics 2009-10-28 Beat Jegerlehner

Lattice simulations on SU(2) and SU(3) gauge theories with matter fields in the fundamental, adjoint and two index symmetric representations are needed to determine if these theories are near or within the conformal window as required for…

High Energy Physics - Lattice · Physics 2015-06-03 T. Karavirta , K. Rummukainen , K. Tuominen

A preconditioning for the Wilson fermion matrix on the lattice is defined which is particularly suited to the case when the temporal lattice spacing is much smaller than the spatial one. Details on the implementation of the scheme are…

High Energy Physics - Lattice · Physics 2015-05-14 Balint Joo , Robert G. Edwards , Michael J. Peardon

We discuss the implementation of a Sheikholeslami-Wohlert term for simulations of lattice QCD with dynamical Wilson fermions as required by Symanzik's improvement program. We show that for the Hybrid Monte Carlo or Kramers equation…

High Energy Physics - Lattice · Physics 2009-10-28 Karl Jansen , Chuan Liu

We report on a parallelized implementation of SSOR preconditioning for O(a) improved lattice QCD with Schr\"odinger functional boundary conditions. Numerical simulations in the quenched approximation at parameters in the light quark mass…

High Energy Physics - Lattice · Physics 2009-10-31 Marco Guagnelli , Jochen Heitger

We study a variant of the Schwarz-preconditioned HMC algorithm. In contrast to the original proposal of L\"uscher, we apply the domain decomposition in one lattice direction only. This is sufficient to reduce the condition number of the…

High Energy Physics - Lattice · Physics 2008-11-26 Martin Hasenbusch

We perform renormalization group transformations to construct optimally local perfect lattice actions for free scalar fields of any mass. Their couplings decay exponentially. The spectrum is identical to the continuum spectrum, while…

High Energy Physics - Lattice · Physics 2016-12-28 W. Bietenholz

We review the numerical analysis' understanding of Krylov subspace methods for solving (non-hermitian) systems of equations and discuss its implications for lattice gauge theory computations using the example of the Wilson fermion matrix.…

High Energy Physics - Lattice · Physics 2009-10-28 Andreas Frommer

We study non-perturbative improvement in SU(3) lattice gauge theory coupled to fermions in the fundamental and two-index symmetric representations. Our lattice action is defined with hypercubic smeared links incorporated into the…

High Energy Physics - Lattice · Physics 2011-06-07 Yigal Shamir , Benjamin Svetitsky , Evgeny Yurkovsky

The coefficient of the O(a)-improved Sheikholeslami-Wohlert action for Wilson fermions are perturbatively determined at one-loop level and estimated at two-loop level.

High Energy Physics - Lattice · Physics 2009-10-22 Satchidananda Naik

We have technically improved the non-perturbative renormalization method, proposed by Martinelli et al., by using quark momentum sources and sinks. Composite two-fermion operators up to three derivatives have been measured for Wilson…

High Energy Physics - Lattice · Physics 2008-11-26 M. Goeckeler , R. Horsley , H. Oelrich , H. Perlt , P. E. L. Rakow , G. Schierholz , A. Schiller

We discuss the use of renormalization counterterms to restore the chiral gauge symmetry in a lattice theory of Wilson fermions. We show that a large class of counterterms can be implemented automatically by making a simple modification to…

High Energy Physics - Lattice · Physics 2014-11-17 Geoffrey T. Bodwin , Eve V. Kovacs

We describe a way to optimize the chiral behavior of Wilson-type lattice fermion actions by studying the low energy real eigenmodes of the Dirac operator. We find a candidate action, the clover action with fat links with a tuned clover…

High Energy Physics - Lattice · Physics 2007-05-23 Thomas DeGrand , Anna Hasenfratz , Tamás G. Kovács

We show that it is possible to construct a lattice Schroedinger functional for standard Wilson fermions, where the expectation values of ${\cal R}_5$-even operators are O($a$) improved, up to terms coming from the boundaries.

High Energy Physics - Lattice · Physics 2007-05-23 Roberto Frezzotti , Giancarlo Rossi

We study some aspects of the ${\cal O}(a)$ improved Sheikholeslami-Wohlert (SW) action for the lattice Schwinger model. We find some improvement concerning the distribution of eigenvalues of the Dirac operator and of the masses but little…

High Energy Physics - Lattice · Physics 2010-11-19 Ch. Hoelbling , C. B. Lang , R. Teppner
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