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Related papers: Full QCD Algorithms towards the Chiral Limit

200 papers

We present first, exploratory results of a hybrid Monte-Carlo algorithm for dynamical, n_f=2, four-dimensional QCD with overlap fermions. As expected, the computational requirements are typically two orders of magnitude larger for the…

High Energy Physics - Lattice · Physics 2010-02-03 Z. Fodor , S. D. Katz , K. K. Szabo

We describe an implementation of the Rational Hybrid Monte Carlo (RHMC) algorithm for dynamical computations with two flavours of staggered quarks. We discuss several variants of the method, the performance and possible sources of error for…

High Energy Physics - Lattice · Physics 2009-11-10 M. A. Clark , A. D. Kennedy

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

We present a detailed design of a (P)HMC simulation algorithm for N_f = 2 + 1 + 1 maximally twisted Wilson quark flavours. The algorithm retains even/odd and mass-shift preconditionings combined with multiple Molecular Dynamics time scales…

High Energy Physics - Lattice · Physics 2007-05-23 T. Chiarappa , R. Frezzotti , C. Urbach

We discuss algorithms for domain wall fermions focussing on accelerating Hybrid Monte Carlo sampling of gauge configurations. Firstly a new multigrid algorithm for domain wall solvers and secondly a domain decomposed hybrid monte carlo…

High Energy Physics - Lattice · Physics 2022-04-01 Peter A Boyle , Dennis Bollweg , Christopher Kelly , Azusa Yamaguchi

Due to improvements in computer performance and algorithms, the rapidly increasing cost for unquenched Wilson-type fermions with lighter quarks has been ameliorated and new simulations are now possible. Here we present results using two…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , G. Schierholz , W. Schroers , T. Streuer , H. Stüben , J. M. Zanotti

We present an exact pseudofermion action for hybrid Monte Carlo simulation (HMC) of one-flavor domain-wall fermion (DWF), with the effective 4-dimensional Dirac operator equal to the optimal rational approximation of the overlap-Dirac…

High Energy Physics - Lattice · Physics 2014-09-30 Yu-Chih Chen , Ting-Wai Chiu

We compare the Hybrid Monte Carlo (HMC) and the Kramers equation algorithms for simulations of QCD with two flavors of dynamical Wilson fermions and gauge group $SU(2)$. The results for the performance of both algorithms are obtained on…

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

We discuss the impact of various improvements on simulations of dynamical overlap fermions using the Hybrid Monte Carlo algorithm. We focus on the usage of fat links and multiple pseudo-fermion fields.

High Energy Physics - Lattice · Physics 2011-07-18 Thomas DeGrand , Stefan Schaefer

We present an algorithmic study for the simulation of two massless flavors of O(a) improved Wilson quarks with Schroedinger functional boundary conditions. The algorithm used is Hybrid Monte Carlo with two pseudo-fermion fields as proposed…

High Energy Physics - Lattice · Physics 2009-11-10 F. Knechtli , M. Della Morte , J. Rolf , R. Sommer , I. Wetzorke , U. Wolff

The improvement of simulations of QCD with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering is studied on $10^4$ and $12^4$ lattices. As an indicator for decorrelation the topological charge is…

High Energy Physics - Lattice · Physics 2007-05-23 E. -M. Ilgenfritz , W. Kerler , M. Müller-Preussker , H. Stüben

We consider recent progress in algorithms for generating gauge field configurations that include the dynamical effects of light fermions. We survey what has been achieved in recent state-of-the-art computations, and examine the trade-offs…

High Energy Physics - Lattice · Physics 2009-11-10 A. D. Kennedy

We simulate Quantum Chromodynamics (QCD) in four Euclidean dimensions with two (degenerate mass) flavors of dynamical quarks. The Dirac operator we use is the so-called chirally improved Dirac operator. We discuss the algorithm used for the…

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

We describe a new Hybrid Monte Carlo (HMC) algorithm for dynamical overlap fermions, which improves the rate of topological index changes by adding an additional (intensive) term to the action for the molecular dynamics part of the…

High Energy Physics - Lattice · Physics 2012-02-28 Nigel Cundy , Weonjong Lee

The performance of the two-step multiboson (TSMB) algorithm is investigated in comparison with the hybrid Monte Carlo (HMC) method for compact lattice QED with standard Wilson fermions both in the Coulomb and confinement phases. The…

High Energy Physics - Lattice · Physics 2015-06-25 I. L. Bogolubsky , V. K. Mitrjushkin , I. Montvay , M. Mueller-Preussker , N. V. Zverev

We introduce a new algorithm which we call the {Rational Hybrid Monte Carlo} Algorithm (RHMC). This method uses a rational approximation to the fermionic kernel together with a noisy Kennedy-Kuti acceptance step to give an efficient…

High Energy Physics - Lattice · Physics 2009-10-31 Ivan Horvath , A. D. Kennedy , Stefan Sint

Results from two studies of full QCD with two flavours of dynamical Wilson fermions are presented. At beta=5.6, the region 0.83 > m_pi/m_rho > 0.56 at m_pia > 0.23 L^{-1} is explored. The SESAM collaboration has generated ensembles of about…

Parallel tempering simulates at many quark masses simultaneously, by changing the mass during the simulation while remaining in equilibrium. The algorithm is faster than pure HMC if more than one mass is needed, and works better the smaller…

High Energy Physics - Lattice · Physics 2009-10-30 G. Boyd

Hasenbusch has proposed splitting the pseudo-fermionic action into two parts, in order to speed-up Hybrid Monte Carlo simulations of QCD. We have tested a different splitting, also using clover-improved Wilson fermions. An additional…

High Energy Physics - Lattice · Physics 2008-11-26 A. Ali Khan , T. Bakeyev , M. Göckeler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , H. Stüben

We present results of a hybrid Monte-Carlo algorithm for dynamical, $n_f=2$, four-dimensional QCD with overlap fermions. The fermionic force requires careful treatment, when changing topological sectors. The pion mass dependence of the…

High Energy Physics - Lattice · Physics 2009-11-10 Z. Fodor , S. D. Katz , K. K. Szabo