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This paper introduces a novel approach to algebraic multigrid methods for large systems of linear equations coming from finite element discretizations of certain elliptic second order partial differential equations. Based on a discrete…

Numerical Analysis · Mathematics 2020-11-30 Lukas Kogler , Joachim Schöberl

This contribution presents a hierarchical multigrid approach for the solution of large-scale finite cell problems on both uniform grids and multi-level hp-discretizations. The proposed scheme leverages the hierarchical nature of the basis…

Numerical Analysis · Mathematics 2021-09-08 John Jomo , Oguz Oztoprak , Frits de Prenter , Nils Zander , Stefan Kollmannsberger , Ernst Rank

The locally optimal block preconditioned conjugate gradient (LOBPCG) algorithm is a popular approach for computing a few smallest eigenvalues and the corresponding eigenvectors of a large Hermitian positive definite matrix A. In this work,…

Numerical Analysis · Mathematics 2024-05-06 Daniel Kressner , Yuxin Ma , Meiyue Shao

In this paper we construct and analyse a level-dependent coarsegrid correction scheme for indefinite Helmholtz problems. This adapted multigrid method is capable of solving the Helmholtz equation on the finest grid using a series of…

Numerical Analysis · Mathematics 2013-09-09 Siegfried Cools , Bram Reps , Wim Vanroose

We prove the uniform convergence of the geometric multigrid V-cycle for hybrid high-order (HHO) and other discontinuous skeletal methods. Our results generalize previously established results for HDG methods, and our multigrid method uses…

Numerical Analysis · Mathematics 2024-04-11 Daniele A. Di Pietro , Zhaonan Dong , Guido Kanschat , Pierre Matalon , Andreas Rupp

Due to its optimal complexity, the multigrid (MG) method is one of the most popular approaches for solving large-scale linear systems arising from the discretization of partial differential equations. However, the parallel implementation of…

Numerical Analysis · Mathematics 2025-02-27 Hardik Kothari , Maria Giuseppina Chiara Nestola , Marco Favino , Rolf Krause

This study presents a novel mixed-precision iterative refinement algorithm, GADI-IR, within the general alternating-direction implicit (GADI) framework, designed for efficiently solving large-scale sparse linear systems. By employing…

Numerical Analysis · Mathematics 2025-03-24 Jifeng Ge , Juan Zhang

The Cholesky decomposition is a fundamental tool for solving linear systems with symmetric and positive definite matrices which are ubiquitous in linear algebra, optimization, and machine learning. Its numerical stability can be improved by…

Machine Learning · Computer Science 2025-07-29 Filip de Roos , Fabio Muratore

We consider the numerical solution of Poisson's equation on structured grids using geometric multigrid with nonstandard coarse grids and coarse level operators. We are motivated by the problem of developing high-order accurate numerical…

Numerical Analysis · Mathematics 2020-08-11 Kamala Liu , William D. Henshaw

In this paper, we develop a multigrid method on unstructured shape-regular grids. For a general shape-regular unstructured grid of ${\cal O}(N)$ elements, we present a construction of an auxiliary coarse grid hierarchy on which a geometric…

Numerical Analysis · Mathematics 2014-10-09 Lars Grasedyck , Lu Wang , Jinchao Xu

A new hybrid algorithm for LDU-factorization for large sparse matrix combining iterative solver, which can keep the same accuracy as the classical factorization, is proposed. The last Schur complement will be generated by iterative solver…

Numerical Analysis · Mathematics 2022-08-04 Atsushi Suzuki

We present a polynomial multigrid method for the nodal interior penalty formulation of the Poisson equation on three-dimensional Cartesian grids. Its key ingredient is a weighted overlapping Schwarz smoother operating on element-centered…

Numerical Analysis · Computer Science 2016-12-19 Joerg Stiller

A numerical algorithm for solving mantle convection problems with strongly variable viscosity is presented. Equations for conservation of mass and momentum for highly viscous and incompressible fluids are solved iteratively by a multigrid…

Geophysics · Physics 2009-11-10 Masanori Kameyama , Akira Kageyama , Tetsuya Sato

We present augmented Lagrangian Schur complement preconditioners and robust multigrid methods for incompressible Stokes problems with extreme viscosity variations. Such Stokes systems arise, for instance, upon linearization of nonlinear…

Numerical Analysis · Mathematics 2021-11-03 Yu-hsuan Shih , Georg Stadler , Florian Wechsung

We introduce a geometric multigrid method for solving linear systems arising from variational problems on surfaces in geometry processing, Gravo MG. Our scheme uses point clouds as a reduced representation of the levels of the multigrid…

Computational Geometry · Computer Science 2023-07-12 Ruben Wiersma , Ahmad Nasikun , Elmar Eisemann , Klaus Hildebrandt

The immersed boundary (IB) method is an approach to fluid-structure interaction that uses Lagrangian variables to describe the structure and Eulerian variables to describe the fluid. Explicit time stepping schemes for the IB method require…

Numerical Analysis · Mathematics 2017-04-06 Robert D. Guy , Bobby Philip , Boyce E. Griffith

The aim of this paper is to design an efficient multigrid method for constrained convex optimization problems arising from discretization of some underlying infinite dimensional problems. Due to problem dependency of this approach, we only…

Optimization and Control · Mathematics 2016-02-12 Michal Kocvara , Sudaba Mohammed

Overlapping block smoothers efficiently damp the error contributions from highly oscillatory components within multigrid methods for the Stokes equations but they are computationally expensive. This paper is concentrated on the development…

Numerical Analysis · Mathematics 2020-08-21 Lisa Claus , Matthias Bolten

This research investigates using a mixed-precision iterative refinement method using posit numbers instead of the standard IEEE floating-point format. The method is applied to solve a general linear system represented by the equation $Ax =…

Numerical Analysis · Mathematics 2024-08-28 James Quinlan , E. Theodore L. Omtzigt

Due to the wide separation of time scales in geophysical fluid dynamics, semi-implicit time integrators are commonly used in operational atmospheric forecast models. They guarantee the stable treatment of fast (acoustic and gravity) waves,…

Computational Physics · Physics 2020-12-30 Christopher Maynard , Thomas Melvin , Eike Hermann Müller
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