Results 51 to 60 of about 78,319 (219)

Krylov Subspace Restarting for Matrix Laplace Transforms

SIAM Journal on Matrix Analysis and Applications, 2023
A common way to approximate $F(A)b$ -- the action of a matrix function on a vector -- is to use the Arnoldi approximation. Since a new vector needs to be generated and stored in every iteration, one is often forced to rely on restart algorithms which are either not efficient, not stable or only applicable to restricted classes of functions.
Andreas Frommer, Karsten Kahl, Marcel Schweitzer, Manuel Tsolakis   +3 more
openaire   +3 more sources

Probing and Graph Coloring Techniques for Trace Estimation in Lattice QCD

Proceedings in Applied Mathematics and Mechanics, Volume 26, Issue 4, December 2026.
ABSTRACT The computation of Tr[D−1]$\mathrm{Tr}[D^{-1}]$, where D$D$ is the Wilson–Dirac matrix of Lattice QCD, is a fundamental and computationally demanding task with applications to disconnected hadronic correlation functions. Since D−1$D^{-1}$ is a dense matrix of prohibitive size, its trace cannot be computed exactly, and one must resort to ...
Mario Papace, Andreas Frommer, Jose Jimenez‐Merchan, Bruno Lang, Gustavo Ramirez‐Hidalgo, Christian Schneider   +5 more
wiley   +1 more source

A Geometric Multigrid Preconditioner for Discontinuous Galerkin Shifted Boundary Method

International Journal for Numerical Methods in Engineering, Volume 127, Issue 21, 15 November 2026.
ABSTRACT I introduce a geometric multigrid preconditioner for the Shifted Boundary Method (SBM) designed to solve PDEs on complex geometries. While the SBM simplifies mesh generation by using a nonconforming background grid, it often results in nonsymmetric linear systems, a complete analysis of which is missing from the literature, especially with ...
Michał Wichrowski
wiley   +1 more source

Sparse Regularization Least-Squares Reverse Time Migration Based on the Krylov Subspace Method

Remote Sensing
Least-squares reverse time migration (LSRTM) is an advanced seismic imaging technique that reconstructs subsurface models by minimizing the residuals between simulated and observed data. Mathematically, the LSRTM inversion of the sub-surface reflectivity
Guangshuai Peng, Xiangbo Gong, Shuang Wang, Zhiyu Cao, Zhuo Xu   +4 more
doaj   +1 more source

ILU preconditioning based on the FAPINV algorithm [PDF]

Opuscula Mathematica, 2015
A technique for computing an ILU preconditioner based on the factored approximate inverse (FAPINV) algorithm is presented. We show that this algorithm is well-defined for H-matrices.
Davod Khojasteh Salkuyeh, Amin Rafiei, Hadi Roohani   +2 more
doaj   +1 more source

Subspace Acceleration for Efficient Nonlinear Water Wave Simulation

International Journal for Numerical Methods in Fluids, Volume 98, Issue 10, Page 1165-1180, October 2026.
We introduce an exponentially weighted subspace acceleration technique to reduce GMRES iterations for solving the Poisson equation with time‐dependent coefficients in nonlinear, dispersive free‐surface flows governed by the incompressible Navier‐Stokes equations. The method significantly reduces memory requirements and computational complexity compared
Rasmus Kleist Hørlyck Sørensen, Margherita Guido, Allan Peter Engsig‐Karup, Daniel Kressner   +3 more
wiley   +1 more source

Polynomial Preconditioning for Indefinite Matrices

Numerical Linear Algebra with Applications, Volume 33, Issue 5, October 2026.
ABSTRACT Polynomial preconditioning is an important tool in solving large linear systems and eigenvalue problems. A polynomial from GMRES can be used to precondition restarted GMRES and restarted Arnoldi. Here we give methods for indefinite matrices that make polynomial preconditioning more generally applicable. The new techniques include balancing the
Hayden Henson, Ronald B. Morgan
wiley   +1 more source

THE COMPARISON OF PRECONDITIONED SYSTEFOR KRYLOV SUBSPACE METHODSM [PDF]

, 2016
The problem of large-scale systems of linear equations, we describe the comparison of preconditioned system for Krylov subspace methods. We used the preconditioned system in Krylov subspace methods, and we compared various preconditioned ...
宮野 駿
core  

Dynamics of monitored SSH model in Krylov space: from complexity to quantum Fisher information

Journal of High Energy Physics
In this paper, we investigate the dynamics of a non-Hermitian Su-Schrieffer-Heeger model that arises out of the no-click limit of a monitored SSH model in the Krylov space.
Nilachal Chakrabarti, Neha Nirbhan, Arpan Bhattacharyya   +2 more
doaj   +1 more source

On Numerical Approximations of the Koopman Operator

Mathematics, 2022
We study numerical approaches to computation of spectral properties of composition operators. We provide a characterization of Koopman Modes in Banach spaces using Generalized Laplace Analysis.
Igor Mezić
doaj   +1 more source