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Related papers: Improvement of algorithms for dynamical overlap fe…

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We describe a Fourier Accelerated Hybrid Monte Carlo algorithm suitable for dynamical fermion simulations of non-gauge models. We test the algorithm in supersymmetric quantum mechanics viewed as a one-dimensional Euclidean lattice field…

High Energy Physics - Lattice · Physics 2011-07-28 S. Catterall , S. Karamov

We perform numerical simulations of lattice QCD with two flavors of dynamical overlap quarks, which have exact chiral symmetry on the lattice. While this fermion discretization is computationally demanding, we demonstrate the feasibility to…

We report on a calculation of $B_K$ with two-flavor dynamical overlap fermions on a $16^3 \times 32$ lattice at $a\sim 0.12$ fm. The results are compared with the PQChPT prediction of quark mass dependence. The systematic errors due to…

High Energy Physics - Lattice · Physics 2008-11-26 JLQCD Collaboration , N. Yamada , S. Aoki , H. Fukaya , S. Hashimoto , J. Noaki , T. Kaneko , H. Matsufuru , T. Onogi

The increase with time of computer resources devoted to simulations of full QCD is spectacular. Yet the reduction of systematic errors is comparatively slow. This is due to the algorithmic complexity of the problem. I review, in elementary…

High Energy Physics - Lattice · Physics 2007-05-23 Philippe de Forcrand

We present results from simulations of two flavors of dynamical overlap fermions on 8^4 lattices at three values of the sea quark mass and a lattice spacing of about 0.16 fm. We measure the topological susceptibility and the chiral…

High Energy Physics - Lattice · Physics 2009-11-11 Thomas DeGrand , Stefan Schaefer

This is the write-up of three lectures on algorithms for dynamical fermions that were given at the ILFTN workshop 'Perspectives in Lattice QCD' in Nara during November 2005. The first lecture is on the fundamentals of Markov Chain Monte…

High Energy Physics - Lattice · Physics 2012-02-24 A. D. Kennedy

We carry out a comparative study among five-dimensional formulations of chirally symmetric fermions about the algorithmic performance, chiral symmetry violation and topological tunneling to find a computationally inexpensive formulation…

High Energy Physics - Lattice · Physics 2013-11-28 The JLQCD Collaboration , T. Kaneko , S. Aoki , G. Cossu , H. Fukaya , S. Hashimoto , J. Noaki

We propose a modification of the Hybrid-Monte-Carlo algorithm that allows for a larger step-size of the integration scheme at constant acceptance rate. The key ingredient is the splitting of the pseudo-fermion action into two parts. We test…

High Energy Physics - Lattice · Physics 2015-06-25 M. Hasenbusch , K. Jansen

The past few years have seen considerable progress in algorithmic development for the generation of gauge fields including the effects of dynamical fermions. The Rational Hybrid Monte Carlo (RHMC) algorithm, where Hybrid Monte Carlo is…

High Energy Physics - Lattice · Physics 2008-11-26 M. A. Clark

We present Monte Carlo simulation results for the three dimensional Thirring model on moderate sized lattices using a hybrid molecular dynamics algorithm which permits an odd or non-integer number Nf of fermion flavors. We find a continuous…

High Energy Physics - Lattice · Physics 2009-10-31 Simon Hands , Biagio Lucini

We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally)…

High Energy Physics - Lattice · Physics 2015-10-27 T. Chiarappa , K. Jansen , K. -I. Nagai , M. Papinutto , L. Scorzato , A. Shindler , C. Urbach , U. Wenger , I. Wetzorke

Three topics concerning fermion simulation algorithms are discussed: 1.) A performance comparison of the multiboson technique to simulate dynamical fermions and the Kramers equation algorithm, 2.) the question of reversibility in the Hybrid…

High Energy Physics - Lattice · Physics 2007-05-23 Karl Jansen , Beat Jegerlehner , Chuan Liu

We test the scaling behaviour of Wilson, hypercube, maximally twisted mass and overlap fermion actions in dynamical simulations of the 2-dimensional massive Schwinger model. We also present possibilities to simulate overlap fermions…

High Energy Physics - Lattice · Physics 2007-05-23 Nils Christian , Karl Jansen , Kei-ichi Nagai , Beatrix Pollakowski

The advantages of using Multi-Step corrections for simulations of lattice gauge theories with dynamical fermions will be discussed. This technique is suited for algorithms based on the Multi-Boson representation of the dynamical fermions as…

High Energy Physics - Lattice · Physics 2008-11-26 Enno E. Scholz , Istvan Montvay

We propose a new method for Hybrid Monte Carlo (HMC) simulations with odd numbers of dynamical fermions on the lattice. It employs a different approach from polynomial or rational HMC. In this method, gamma-five hermiticity of the lattice…

High Energy Physics - Lattice · Physics 2015-05-27 Kenji Ogawa

The overlap hypercube fermion is a variant of a chirally symmetric lattice fermion, which is endowed with a higher level of locality than the standard overlap fermion. We apply this formulation in quenched QCD simulations with light quarks.…

High Energy Physics - Lattice · Physics 2009-11-11 W. Bietenholz , S. Shcheredin

The numerical and computational aspects of chiral fermions in lattice quantum chromodynamics are extremely demanding. In the overlap framework, the computation of the fermion propagator leads to a nested iteration where the matrix vector…

High Energy Physics - Lattice · Physics 2009-11-10 Nigel Cundy , Andreas Frommer , Jasper van den Eshof , Thomas Lippert , Stephan Krieg , Katrin Schäfer

I review the lattice formulations of vector-like gauge theories (e.g. QCD) with domain-wall/overlap fermions, and discuss how to optimize the chiral symmetry for any finite $ N_s $ (sites in the fifth dimension). In this formulation, quark…

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu

The overlap fermion offers the tremendous advantage of exact chiral symmetry on the lattice, but is numerically intensive. This can be made affordable while still providing large lattice volumes, by using coarse lattice spacing, given that…

High Energy Physics - Lattice · Physics 2014-11-17 Terrence Draper , Nilmani Mathur , Jianbo Zhang , Andrei Alexandru , Ying Chen , Shao-Jing Dong , Ivan Horvath , Frank Lee , Sonali Tamhankar

We report on the two-flavor QCD simulation in the epsilon-regime using the overlap fermion formulation. Sea quark mass is reduced to ~ 2 MeV on a 16^3x32 lattice with the lattice spacing ~ 0.11fm. Topological charge is fixed at Q=0. We…

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