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Related papers: Improvement of algorithms for dynamical overlap fe…

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We review a number of topics related to block variable renormalisation group transformations of quantum fields on the lattice, and to the emerging perfect lattice actions. We first illustrate this procedure by considering scalar fields.…

High Energy Physics - Lattice · Physics 2008-11-26 W. Bietenholz

As a prerequisite to dynamical fermion simulations a detailed study of optimal parameters and scaling behavior is conducted for the quenched Schr\"odinger functional at fixed renormalized coupling. We compare standard hybrid overrelaxation…

High Energy Physics - Lattice · Physics 2015-06-25 Bernd Gehrmann , Ulli Wolff

I discuss the behaviour of algorithms for dynamical fermions as the sea-quark mass decreases. I focus on the Hybrid-Monte-Carlo (HMC) algorithm applied to two degenerate flavours of Wilson fermions. First, I briefly review the performance…

High Energy Physics - Lattice · Physics 2009-11-10 Martin Hasenbusch

Smearing the gauge links of dynamical configurations removes small scale unphysical vacuum fluctuations and thus improves the chiral properties of lattice fermions. Recently we proposed the hypercubic smearing (HYP) that improves the flavor…

High Energy Physics - Lattice · Physics 2007-05-23 A. Hasenfratz , F. Knechtli

Within the overlap framework, I derive the main formulae one finds today in papers touting a ``new approach'' to the regularization of chiral gauge theories. My main objective is to clear up an unhealthy confusion about how many successful…

High Energy Physics - Lattice · Physics 2007-05-23 H. Neuberger

Some results in QCD_2 at large N are presented using the reduced model on the lattice. Overlap fermions are used to compute meson propagators.

High Energy Physics - Lattice · Physics 2009-11-07 J. Kiskis , R. Narayanan. H. Neuberger

Using a reweighting technique combined with a low-mode truncation of the fermionic determinant, we estimate the quark-mass dependence of the QCD topological susceptibility with overlap fermions. In contrast to previous lattice simulations…

High Energy Physics - Lattice · Physics 2009-09-25 Tamas G. Kovacs

We discuss the lattice formulation of gauge theories with fermions in arbitrary representations of the color group, and present the implementation of the RHMC algorithm for simulating dynamical Wilson fermions. A first dataset is presented…

High Energy Physics - Lattice · Physics 2010-01-21 Luigi Del Debbio , Agostino Patella , Claudio Pica

We simulate two dynamical, mass degenerate light quarks on 16^3x32 lattices with a spatial extent of 2.4 fm using the Chirally Improved Dirac operator. The simulation method, the implementation of the action and signals of equilibration are…

High Energy Physics - Lattice · Physics 2009-11-06 Christof Gattringer , Christian Hagen , C. B. Lang , Markus Limmer , Daniel Mohler , Andreas Schäfer

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 propose a simple iterative algorithm to construct the optimal multi-configuration approximation of an $N$-fermion wave function. That is, $M\geq N $ single-particle orbitals are sought iteratively so that the projection of the given wave…

Quantum Physics · Physics 2014-01-10 J. M. Zhang , Marcus Kollar

We introduce a numerical algorithm to stochastically sample the dual fermion perturbation series around the dynamical mean field theory, generating all topologies of two-particle interaction vertices. We show results in the weak and strong…

Strongly Correlated Electrons · Physics 2016-07-07 Sergei Iskakov , Andrey E. Antipov , Emanuel Gull

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

Representing massless Dirac fermions on a spatial lattice poses a potential challenge known as the Fermion Doubling problem. Addition of a quadratic term to the Dirac Hamiltonian circumvents this problem. We show that the modified…

Mesoscale and Nanoscale Physics · Physics 2015-09-15 K. M. Masum Habib , Redwan N. Sajjad , Avik W. Ghosh

We briefly review the overlap formalism for chiral gauge theories, the overlap Dirac operator for massless fermions and its connection to domain wall fermions. We describe properties of the overlap Dirac operator, and methods to implement…

High Energy Physics - Lattice · Physics 2007-05-23 Robert G. Edwards , Urs M. Heller , Joe Kiskis , Rajamani Narayanan

We present results of a quenched QCD simulation with overlap fermions on a lattice of volume V = 16^3X32 at beta=6.0, which corresponds approximatively to a lattice cutoff of 2 GeV and an extension of 1.4 fm. From the two-point correlation…

High Energy Physics - Lattice · Physics 2015-06-25 L. Giusti , C. Hoelbling , C. Rebbi

Problems in lattice gauge models with fermions are discussed. A new bosonic Hermitean effective action for lattice QCD with dynamical quarks is presented. In distinction of the previous version, it does not include constraints and is better…

High Energy Physics - Theory · Physics 2007-05-23 A. A. Slavnov

The Hybrid Monte Carlo algorithm is adapted to the simulation of a system of classical degrees of freedom coupled to non self-interacting lattices fermions. The diagonalization of the Hamiltonian matrix is avoided by introducing a…

Strongly Correlated Electrons · Physics 2009-10-31 J. L. Alonso , L. A. Fernandez , F. Guinea , V. Laliena , V. Martin-Mayor

A previously introduced multi-boson technique for the simulation of QCD with dynamical quarks is described and some results of first test runs on a $6^3\times12$ lattice with Wilson quarks and gauge group SU(2) are reported.

High Energy Physics - Lattice · Physics 2009-10-22 B. Bunk , K. Jansen , B. Jegerlehner , M. Lüscher , H. Simma , R. Sommer

We argue that lattice simulations of full QCD with varying quark mass are best conducted at fixed lattice spacing rather than at fixed $\beta$. We present techniques which enable this to be carried out effectively, namely the tuning in bare…

High Energy Physics - Lattice · Physics 2009-10-31 Alan C. Irving , UKQCD Collaboration