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Related papers: Low-Lying Fermion Modes: Dynamical versus Quenched

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We present preliminary results for the topological charge and susceptibility determined from the low-lying eigenmodes of the Wilson-Dirac operator. These modes have been computed on dynamical configurations with Nf=2 non-perturbatively…

High Energy Physics - Lattice · Physics 2015-06-25 R. Horsley , T. G. Kovacs , V. Linke , D. Pleiter , G. Schierholz

We investigate the distribution of low-lying eigenmodes of hermitian Wilson-Dirac operator, $H_W$, with the gauge action whose form is designed to avoid topology change, as well as with the standard plaquette action. On the quenched…

High Energy Physics - Lattice · Physics 2009-04-25 H. Fukaya , S. Hashimoto , T. Hirohashi , H. Matsufuru , K. Ogawa , T. Onogi

The spectral flow of the low-lying eigenvalues of the improved and unimproved Wilson-Dirac operator is studied on instanton-like configurations and on thermalized quenched configurations at various $\beta$-values and lattice sizes. We also…

High Energy Physics - Lattice · Physics 2007-05-23 Hubert Simma , Douglas Smith

An exploratory study of the low-lying eigenvalues of the Wilson-Dirac operator and their corresonding eigenvectors is presented. Results for the eigenvalues from quenched and unquenched simulations are discussed. The eigenvectors are…

High Energy Physics - Lattice · Physics 2009-10-28 K. Jansen , C. Liu , H. Simma , D. Smith

Several lattice calculations which probe the chiral and topological structure of QCD are discussed. The results focus attention on the low-lying eigenmodes of the Dirac operator in typical gauge field configurations.

High Energy Physics - Lattice · Physics 2009-10-31 H. B. Thacker

Measurements of the lowest-lying eigenvalues of the staggered fermion Dirac operator are made on ensembles of equilibrium gauge field configurations in quenched SU(3) lattice gauge theory. The results are compared with exact analytical…

High Energy Physics - Lattice · Physics 2009-10-31 P. H. Damgaard , U. M. Heller , A. Krasnitz

We investigate the spectral properties of the Wilson Dirac operator in quenched QCD in the microscopic regime. We distinguish the topological sectors using the index as determined by the Wilson flow method. Consequently, the distributions…

High Energy Physics - Lattice · Physics 2012-01-04 Albert Deuzeman , Urs Wenger , Jair Wuilloud

We investigate the effects of low-lying fermion eigenmodes on the QCD partition function in the $\epsilon$-regime. The fermion determinant is approximated by a truncated product of low-lying eigenvalues of the overlap-Dirac operator. With…

High Energy Physics - Lattice · Physics 2009-11-11 Kenji Ogawa , Shoji Hashimoto

We have constructed the lowest few eigenvectors of the staggered Dirac operator on SU(3) gauge configurations, both quenched and dynamical. We use these modes to study the topological charge and to construct approximate hadronic…

High Energy Physics - Lattice · Physics 2009-10-30 Lakshmi Venkataraman , Gregory Kilcup

We apply the topology conserving gauge action proposed by Luescher to the four-dimensional lattice QCD simulation in the quenched approximation. With this gauge action the topological charge is stabilized along the hybrid Monte Carlo…

High Energy Physics - Lattice · Physics 2009-11-11 H. Fukaya , S. Hashimoto , T. Hirohashi , K. Ogawa , T. Onogi

We investigate the effects of low-lying fermion modes on the QCD partition function in the epsilon-regime. With the overlap Dirac operator we calculate several tens of low-lying fermion eigenvalues on the quenched lattice. By partially…

High Energy Physics - Lattice · Physics 2009-11-10 Kenji Ogawa , Shoji Hashimoto

We consider properties of zero and near-zero modes for overlap fermion operator in SU(2) lattice gluodynamics. The density of the states is of the order of Lambda(QCD) while the localization volume of the modes tends to zero in physical…

High Energy Physics - Lattice · Physics 2007-05-23 M. I. Polikarpov , F. V. Gubarev , S. M. Morozov , V. I. Zakharov

The probability density of low-lying eigenvectors of the hermitian Wilson-Dirac operator is examined. Comparisons in position and size between eigenvectors, topological charge and action density are made. We do this for standard Monte-Carlo…

High Energy Physics - Lattice · Physics 2010-03-04 Daniel-Jens Kusterer , John Hedditch , Waseem Kamleh , Derek B. Leinweber , Anthony G. Williams

We present a study of the instanton size and spatial distributions in pure SU(3) gauge theory using under-relaxed cooling. We also investigate the low-lying eigenmodes of the (improved) Wilson-Dirac operator, in particular, the appearance…

High Energy Physics - Lattice · Physics 2009-10-30 D. Smith , H. Simma , M. Teper

We describe and test a method known in the literature as low mode averaging to improve Euclidean two-point functions in lattice QCD using the low-lying eigenmodes of the Wilson-Dirac operator D. The contribution from the low modes is…

High Energy Physics - Lattice · Physics 2011-04-20 Gunnar Bali , Luca Castagnini , Sara Collins

We discuss some properties of zero and near-zero modes of the Dirac operator, as observed in a recent simulation of 2-flavor QCD. The quarks have been implemented with the so-called Chirally Improved Dirac operator, which obeys the…

High Energy Physics - Lattice · Physics 2007-05-23 C. B. Lang , Pushan Majumdar , Wolfgang Ortner

We perform a systematic study of low-lying eigenmodes of $H_w$ with various gauge actions to find the optimal choice for dynamical overlap fermion simulations, with which one may achieve lower numerical cost for HMC and better locality…

High Energy Physics - Lattice · Physics 2008-11-26 JLQCD Collaboration , N. Yamada , S. Aoki , H. Fukaya , S. Hashimoto , K-I. Ishikawa , K. Kanaya , T. Kaneko , H. Matsufuru , M. Okamoto , T. Onogi

The spectral properties of the Wilson-Dirac operator in 2-dimensional QED responsible for the appearance of exceptional configurations in quenched simulations are studied in detail. The mass singularity structure of the quenched functional…

High Energy Physics - Lattice · Physics 2009-10-30 W. Bardeen , A. Duncan , E. Eichten , H. Thacker

We study characteristic features of the eigenvalues of the Wilson-Dirac operator in topologically non-trivial gauge field configurations by examining complete spectra of the fermion matrix. In particular we discuss the role of eigenvectors…

High Energy Physics - Lattice · Physics 2009-10-30 Christof Gattringer , Ivan Hip

We compare the behavior of different lattice Dirac operators in gauge backgrounds which are lattice discretizations of a classical instanton. In particular we analyze the standard Wilson operator, a chirally improved Dirac operator and the…

High Energy Physics - Lattice · Physics 2008-11-26 Christof Gattringer , Meinulf Göckeler , C. B. Lang , P. E. L. Rakow , Andreas Schäfer
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