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Related papers: Krylov space solvers for shifted linear systems

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We review the numerical analysis' understanding of Krylov subspace methods for solving (non-hermitian) systems of equations and discuss its implications for lattice gauge theory computations using the example of the Wilson fermion matrix.…

High Energy Physics - Lattice · Physics 2009-10-28 Andreas Frommer

An approach is given for solving large linear systems that combines Krylov methods with use of two different grid levels. Eigenvectors are computed on the coarse grid and used to deflate eigenvalues on the fine grid. GMRES-type methods are…

Numerical Analysis · Mathematics 2020-05-08 Ronald B. Morgan , Travis Whyte , Walter Wilcox , Zhao Yang

In this work, we propose a reduced basis method for efficient solution of parametric linear systems. The coefficient matrix is assumed to be a linear matrix-valued function that is symmetric and positive definite for admissible values of…

Numerical Analysis · Mathematics 2021-09-28 Antti Autio , Antti Hannukainen

In the present paper, we propose Krylov-based methods for solving large-scale differential Sylvester matrix equations having a low rank constant term. We present two new approaches for solving such differential matrix equations. The first…

Numerical Analysis · Mathematics 2017-07-10 M. Hached , K. Jbilou

Context. Numerical solutions to transfer problems of polarized radiation in solar and stellar atmospheres commonly rely on stationary iterative methods, which often perform poorly when applied to large problems. In recent times, stationary…

Numerical Analysis · Mathematics 2021-12-08 Pietro Benedusi , Gioele Janett , Luca Belluzzi , Rolf Krause

Nowadays, many fields of study are have to deal with large and sparse data matrixes, but the most important issue is finding the inverse of these matrixes. Thankfully, Krylov subspace methods can be used in solving these types of problem.…

Optimization and Control · Mathematics 2018-11-26 Shitao Fan

We investigate optimal choices for the (outer) iteration method to use when solving linear systems with Neuberger's overlap operator in QCD. Different formulations for this operator give rise to different iterative solvers, which are…

High Energy Physics - Lattice · Physics 2007-05-23 G. Arnold , N. Cundy , J. van den Eshof , A. Frommer , S. Krieg , Th. Lippert , K. Schäfer

Krylov subspace methods are an essential building block in numerical simulation software. The efficient utilization of modern hardware is a challenging problem in the development of these methods. In this work, we develop Krylov subspace…

Numerical Analysis · Mathematics 2021-04-07 Nils-Arne Dreier

In this paper I describe a new optimal Krylov subspace solver for shifted unitary matrices called the Shifted Unitary Orthogonal Method (SUOM). This algorithm is used as a benchmark against any improvement like the two-grid algorithm. I use…

High Energy Physics - Lattice · Physics 2009-11-10 Artan Borici

We consider three improvements to seed methods for Hermitian linear systems with multiple right-hand sides: only the Krylov subspace for the first system is used for seeding subsequent right-hand sides, the first right-hand side is solved…

High Energy Physics - Lattice · Physics 2009-03-19 Abdou Abdel-Rehim , Ronald B. Morgan , Walter Wilcox

Among randomized numerical linear algebra strategies, so-called sketching procedures are emerging as effective reduction means to accelerate the computation of Krylov subspace methods for, e.g., the solution of linear systems, eigenvalue…

Numerical Analysis · Mathematics 2024-08-02 Davide Palitta , Marcel Schweitzer , Valeria Simoncini

Application of multigrid solvers in shifted linear systems is studied. We focus on accelerating the rational approximation needed for simulating single flavor operators. This is particularly useful, in the case of twisted mass fermions for…

High Energy Physics - Lattice · Physics 2019-02-20 Constantia Alexandrou , Simone Bacchio , Jacob Finkenrath

We focus on robust and efficient iterative solvers for the pressure Poisson equation in incompressible Navier-Stokes problems. Preconditioned Krylov subspace methods are popular for these problems, with BiCGStab and GMRES(m) most frequently…

Numerical Analysis · Computer Science 2015-09-29 Amit Amritkar , Eric de Sturler , Katarzyna Świrydowicz , Danesh Tafti , Kapil Ahuja

Iterative solvers for large-scale linear systems such as Krylov subspace methods can diverge when the linear system is ill-conditioned, thus significantly reducing the applicability of these iterative methods in practice for…

Numerical Analysis · Mathematics 2025-07-24 Vasileios Kalantzis , Mark S. Squillante , Chai Wah Wu

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

We consider the task of computing solutions of linear systems that only differ by a shift with the identity matrix as well as linear systems with several different right hand sides. In the past Krylov subspace methods have been developed…

High Energy Physics - Lattice · Physics 2012-05-03 Sebastian Birk , Andreas Frommer

A coarse grid correction (CGC) approach is proposed to enhance the efficiency of the matrix exponential and $\varphi$ matrix function evaluations. The approach is intended for iterative methods computing the matrix-vector products with…

Numerical Analysis · Mathematics 2024-04-23 Mike A. Botchev

For the large-scale linear discrete ill-posed problem $\min\|Ax-b\|$ or $Ax=b$ with $b$ contaminated by Gaussian white noise, the Lanczos bidiagonalization based Krylov solver LSQR and its mathematically equivalent CGLS, the Conjugate…

Numerical Analysis · Mathematics 2020-03-20 Zhongxiao Jia

We consider solution of multiply shifted systems of nonsymmetric linear equations, possibly also with multiple right-hand sides. First, for a single right-hand side, the matrix is shifted by several multiples of the identity. Such problems…

Mathematical Physics · Physics 2008-11-26 Dean Darnell , Ronald B. Morgan , Walter Wilcox

We derive an augmented Krylov subspace method with subspace recycling for computing a sequence of matrix function applications on a set of vectors. The matrix is either fixed or changes as the sequence progresses. We assume consecutive…

Numerical Analysis · Mathematics 2025-08-21 Liam Burke , Andreas Frommer , Gustavo Ramirez-Hidalgo , Kirk M. Soodhalter