English
Related papers

Related papers: Improving the dynamical overlap algorithm

200 papers

The probability of accepting a candidate move in the hybrid Monte Carlo algorithm can be increased by considering a transition to be between windows of several states at the beginning and end of the trajectory, with a state within the…

High Energy Physics - Lattice · Physics 2008-02-03 R. M. Neal

I show how to avoid a two level nested conjugate gradient procedure in the context of Hybrid Monte Carlo with the overlap fermionic action. The resulting procedure is quite similar to Hybrid Monte Carlo with domain wall fermions, but is…

High Energy Physics - Lattice · Physics 2016-08-25 Herbert Neuberger

Current dynamical overlap fermion hybrid Monte Carlo simulations encounter large fermionic forces when there is mixing between near zero-eigenvectors of the kernel operator. This leads to low acceptance rates when there is a large density…

High Energy Physics - Lattice · Physics 2009-03-12 Nigel Cundy

We present relaxation and preconditioning techniques which accelerate the inversion of the overlap operator by a factor of four on small lattices, with larger gains as the lattice size increases. These improvements can be used in both…

High Energy Physics - Lattice · Physics 2009-11-10 S. Krieg , N. Cundy , J. van den Eshof , A. Frommer , Th. Lippert , K. Schäfer

We report performance benchmarks for several algorithms that we have used to simulate the Schr"odinger functional with two flavors of dynamical quarks. They include hybrid and polynomial hybrid Monte Carlo with preconditioning. An appendix…

High Energy Physics - Lattice · Physics 2014-11-17 Roberto Frezzotti , Martin Hasenbusch , Jochen Heitger , Karl Jansen , Ulli Wolff

The overlap Dirac operator at nonzero quark chemical potential involves the computation of the sign function of a non-Hermitian matrix. In this talk we present an iterative method, first proposed by us in Ref. [1], which allows for an…

High Energy Physics - Lattice · Physics 2009-01-14 Jacques Bloch , Andreas Frommer , Bruno Lang , Tilo Wettig

We present a classical enhancement to improve the accuracy of the Hybrid variant (Hybrid HHL) of the quantum algorithm for solving linear systems of equations proposed by Harrow, Hassidim, and Lloyd (HHL). We achieve this by using higher…

Quantum Physics · Physics 2024-11-12 Jack Morgan , Eric Ghysels , Hamed Mohammadbagherpoor

We propose a variant of the Simulated Annealing method for optimization in the multivariate analysis of differentiable functions. The method uses global actualizations via the Hybrid Monte Carlo algorithm in their generalized version for…

Statistical Mechanics · Physics 2009-10-30 R. Salazar , R. Toral

The pseudofermion action of the Hybrid Monte Carlo (HMC) algorithm for dynamical fermions is modified to directly incorporate Incomplete LU (ILU) factorisation. This reduces the stochastic noise and allows a larger molecular dynamics…

High Energy Physics - Lattice · Physics 2007-05-23 Mike Peardon

We present the preliminary tests on two modifications of the Hybrid Monte Carlo (HMC) algorithm. Both algorithms are designed to travel much farther in the Hamiltonian phase space for each trajectory and reduce the autocorrelations among…

High Energy Physics - Lattice · Physics 2018-04-18 Guido Cossu , Peter Boyle , Norman Christ , Chulwoo Jung , Andreas Jüttner , Francesco Sanfilippo

We use a continued fraction expansion of the sign-function in order to obtain a five dimensional formulation of the overlap lattice Dirac operator. Within this formulation the inverse of the overlap operator can be calculated by a single…

High Energy Physics - Lattice · Physics 2015-06-25 A. Borici , A. D. Kennedy , B. J. Pendleton , U. Wenger

We construct an $O(a^2)$-improved overlap-Dirac operator by designing an improved overlap kernel, based on the Symanzik improvement program. Field rotation terms are also identified to improve off-shell amplitudes for both massless and…

High Energy Physics - Lattice · Physics 2010-11-05 H. Ikeda , S. Hashimoto

We study the improvement of Kennedy-Kuti's linear accept/reject algorithm with different ordering criterion and modified Bhanot-Kennedy estimator of $e^{\Delta H}$ to reduce probability-bound violation. A new stochastic Monte Carlo…

High Energy Physics - Lattice · Physics 2009-10-31 L. Lin , K. F. Liu , J. Sloan

We propose a practical formulation of the overlap Dirac operator in lattice QCD that employs the diagonal Kenney-Laub rational iterates - expressed via their partial fraction decomposition - to approximate the matrix sign function. We…

High Energy Physics - Lattice · Physics 2025-12-24 Stephan Durr , Stylianos Gregoriou , Giannis Koutsou

We introduce a method that automatically and jointly updates both continuous and discrete parameters of a compound lens design, to improve its performance in terms of sharpness, speed, or both. Previous methods for compound lens design use…

Graphics · Computer Science 2025-09-30 Arjun Teh , Delio Vicini , Bernd Bickel , Ioannis Gkioulekas , Matthew O'Toole

We construct new Ginsparg-Wilson fermions for QCD by inserting an approximately chiral Dirac operator - which involves ingredients of a perfect action - into the overlap formula. This accelerates the convergence of the overlap Dirac…

High Energy Physics - Lattice · Physics 2010-04-05 W. Bietenholz

We propose a multi-level method to increase the accuracy of machine learning algorithms for approximating observables in scientific computing, particularly those that arise in systems modeled by differential equations. The algorithm relies…

Numerical Analysis · Mathematics 2020-07-06 Kjetil O. Lye , Siddhartha Mishra , Roberto Molinaro

We present an efficient low-rank updating algorithm for updating the trial wavefunctions used in Quantum Monte Carlo (QMC) simulations. The algorithm is based on low-rank updating of the Slater determinants. In particular, the computational…

Materials Science · Physics 2009-06-25 Phani K. V. V. Nukala , P. R. C. Kent

We consider the problem of consistently matching multiple sets of elements to each other, which is a common task in fields such as computer vision. To solve the underlying NP-hard objective, existing methods often relax or approximate it,…

Machine Learning · Statistics 2019-07-19 Da Tang , Tony Jebara

In this paper we discuss techniques, which lead to a significant improvement of the efficiency of the Monte Carlo integration, when one-loop QCD amplitudes are calculated numerically with the help of the subtraction method and contour…

High Energy Physics - Phenomenology · Physics 2015-06-05 Sebastian Becker , Christian Reuschle , Stefan Weinzierl