Randomized methods for dynamical low-rank approximation

Fuente: arXiv
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Autore principale: Carrel, Benjamin
Natura: Preprint
Pubblicazione: 2024
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author Carrel, Benjamin
author_facet Carrel, Benjamin
contents We introduce novel dynamical low-rank methods for solving large-scale matrix differential equations, motivated by algorithms from randomized numerical linear algebra. In terms of performance (cost and accuracy), our methods overperform existing dynamical low-rank techniques. Several applications to stiff differential equations demonstrate the robustness, accuracy and low variance of the new methods, despite their inherent randomness. Allowing augmentation of the range and corange, the new methods have a good potential for preserving critical physical quantities such as the energy, mass and momentum. Numerical experiments on the Vlasov-Poisson equation are particularly encouraging. The new methods comprise two essential steps: a range estimation step followed by a post-processing step. The range estimation is achieved through a novel dynamical rangefinder method. Subsequently, we propose two methods for post-processing, leading to two time-stepping methods: dynamical randomized singular value decomposition (DRSVD) and dynamical generalized Nyström (DGN). The new methods naturally extend to the rank-adaptive framework by estimating the error via Gaussian sampling.
format Preprint
id arxiv_https___arxiv_org_abs_2410_17091
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Randomized methods for dynamical low-rank approximation
Carrel, Benjamin
Numerical Analysis
65F55, 65L04, 65L05, 65L80, 65M22, 68W20
We introduce novel dynamical low-rank methods for solving large-scale matrix differential equations, motivated by algorithms from randomized numerical linear algebra. In terms of performance (cost and accuracy), our methods overperform existing dynamical low-rank techniques. Several applications to stiff differential equations demonstrate the robustness, accuracy and low variance of the new methods, despite their inherent randomness. Allowing augmentation of the range and corange, the new methods have a good potential for preserving critical physical quantities such as the energy, mass and momentum. Numerical experiments on the Vlasov-Poisson equation are particularly encouraging. The new methods comprise two essential steps: a range estimation step followed by a post-processing step. The range estimation is achieved through a novel dynamical rangefinder method. Subsequently, we propose two methods for post-processing, leading to two time-stepping methods: dynamical randomized singular value decomposition (DRSVD) and dynamical generalized Nyström (DGN). The new methods naturally extend to the rank-adaptive framework by estimating the error via Gaussian sampling.
title Randomized methods for dynamical low-rank approximation
topic Numerical Analysis
65F55, 65L04, 65L05, 65L80, 65M22, 68W20
url https://arxiv.org/abs/2410.17091