English
Related papers

Related papers: Adaptive Aggregation-based Domain Decomposition Mu…

200 papers

The performance of Federated learning (FL) is negatively affected by device differences and statistical characteristics between participating clients. To address this issue, we introduce a deep unfolding network (DUN)-based technique that…

Machine Learning · Computer Science 2023-07-03 Shanika I Nanayakkara , Shiva Raj Pokhrel , Gang Li

We test the reweighting of the quark determinant of O(a) improved Wilson fermions in the domain-decomposed hybrid Monte-Carlo algorithm. Specifically, we implement a reweighting in a twisted-mass parameter proposed by Palombi and L\"uscher…

High Energy Physics - Lattice · Physics 2011-11-17 Chuan Miao , Harvey B. Meyer , Hartmut Wittig

The microscopic spectral density for lattice QCD with two flavors and maximally twisted mass is computed. The results are given for fixed index of the Dirac operator and include the leading order $a^2$ corrections to the chiral Lagrangian…

High Energy Physics - Lattice · Physics 2013-05-30 K. Splittorff , J. J. M. Verbaarschot

We present a systematic comparison of various iterative methods to obtain the fermion propagator with both overlap and twisted mass fermions at fixed pion mass in the quenched approximation. Taking the best available algorithm in each case…

High Energy Physics - Lattice · Physics 2009-11-10 T. Chiarappa , K. Jansen , K. -I. Nagai , M. Papinutto , L. Scorzato , A. Shindler , C. Urbach , U. Wenger , I. Wetzorke

We report on lattice QCD results for the thermodynamic equation of state of quark-gluon matter obtained with Nf=2 degenerate quark flavors. For the fermion field discretization we are using the Wilson-twisted mass prescription. Simulations…

High Energy Physics - Lattice · Physics 2015-06-23 F. Burger , E. -M. Ilgenfritz , M. P. Lombardo , M. Muller-Preussker

The low-lying eigenvalues of a (sparse) hermitian matrix can be computed with controlled numerical errors by a conjugate gradient (CG) method. This CG algorithm is accelerated by alternating it with exact diagonalisations in the subspace…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas Kalkreuter , Hubert Simma

The motivations for simulating QCD thermodynamics with Wilson fermions and a twisted mass term are introduced. The twisted mass approach provides a natural infrared cutoff and O(a) improvement at maximal twist, and can be extended to finite…

High Energy Physics - Lattice · Physics 2008-11-26 E. -M. Ilgenfritz , M. Müller-Preussker , A. Sternbeck , K. Jansen , I. Wetzorke , M. P. Lombardo , O. Philipsen

Scalable spatial GPs for massive datasets can be built via sparse Directed Acyclic Graphs (DAGs) where a small number of directed edges is sufficient to flexibly characterize spatial dependence. The DAG can be used to devise fast algorithms…

Methodology · Statistics 2025-03-31 Michele Peruzzi , Sudipto Banerjee , David B. Dunson , Andrew O. Finley

We propose improved estimators to compute the reweighting factors which are needed for lattice QCD calculations that rely on twisted-mass reweighting for the light quark contribution and the Rational Hybrid Monte Carlo (RHMC) algorithm for…

High Energy Physics - Lattice · Physics 2024-03-19 Simon Kuberski

At physical light quark masses, efficient linear solvers are crucial for carrying out the millions of inversions of the Dirac matrix required for obtaining high statistics in quark correlation functions. Adaptive algebraic multi-grid…

High Energy Physics - Lattice · Physics 2022-01-12 Shuhei Yamamoto , Simone Bacchio , Jacob Finkenrath

The maximally twisted lattice QCD action of an $SU_f(2)$ doublet of mass degenerate Wilson quarks gives rise to a real positive fermion determinant and it is invariant under the product of standard parity times the change of sign of the…

High Energy Physics - Lattice · Physics 2009-11-10 R. Frezzotti , G. C. Rossi

We propose an adaptive mixed precision and dynamically scaled preconditioned conjugate gradient algorithm (AMP-PCG). It dynamically adjusts the precision for storing vectors and computing, exploiting low precision when appropriate, while…

Numerical Analysis · Mathematics 2025-05-08 Yichen Guo , Eric de Sturler , Tim Warburton

With the ever-growing number of computing architectures, performance portability is an important aspect of (Lattice QCD) software. The Grid library provides a good framework for writing such code, as it thoroughly separates…

High Energy Physics - Lattice · Physics 2019-04-19 Daniel Richtmann , Peter A. Boyle , Tilo Wettig

We summarize four contributions about dynamical twisted mass fermions. The resulting report covers results for N_f=2 obtained from three different gauge actions, namely the standard Wilson plaquette gauge action, the DBW2 and the tree-level…

High Energy Physics - Lattice · Physics 2010-12-23 F. Farchioni , P. Hofmann , K. Jansen , I. Montvay , G. Munster , M. Papinutto , E. E. Scholz , L. Scorzato , A. Shindler , N. Ukita , C. Urbach , U. Wenger , I. Wetzorke

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

The use of multigrid and related preconditioners with the finite element method is often limited by the difficulty of applying the algorithm effectively to a problem, especially when the domain has a complex shape or adaptive refinement. We…

Numerical Analysis · Computer Science 2015-03-19 Peter R. Brune , Matthew G. Knepley , L. Ridgway Scott

Mixed action lattice calculations allow for an additive lattice spacing dependent mass renormalization of mesons composed of one sea and one valence quark, regardless of the type of fermion discretization methods used in the valence and sea…

High Energy Physics - Lattice · Physics 2008-11-26 Kostas Orginos , Andre Walker-Loud

The variational method is used widely for determining eigenstates of the QCD hamiltonian for actions with a conventional transfer matrix, e.g., actions with improved Wilson fermions. An alternative lattice fermion formalism, staggered…

High Energy Physics - Lattice · Physics 2015-03-05 Carleton DeTar , Song-Haeng Lee

We present a new multigrid solver that is suitable for the Dirac operator in the presence of disordered gauge fields. The key behind the success of the algorithm is an adaptive projection onto the coarse grids that preserves the near null…

High Energy Physics - Lattice · Physics 2008-11-26 J. Brannick , R. C. Brower , M. A. Clark , J. C. Osborn , C. Rebbi

The structure of an effective light-cone Hamiltonian as recently derived is analyzed with emphasis on its prediction for flavor mixing in physical mesons. In a (perhaps over-simplified) model with one adjustable parameter, the empirical…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hans-Christian Pauli