Accelerating a restarted Krylov method for matrix functions with randomization

Fuente: arXiv
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Autori principali: Guidotti, Nicolas L., Martinsson, Per-Gunnar, Acebrón, Juan A., Monteiro, José
Natura: Preprint
Pubblicazione: 2025
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author Guidotti, Nicolas L.
Martinsson, Per-Gunnar
Acebrón, Juan A.
Monteiro, José
author_facet Guidotti, Nicolas L.
Martinsson, Per-Gunnar
Acebrón, Juan A.
Monteiro, José
contents Many scientific applications require the evaluation of the action of the matrix function over a vector and the most common methods for this task are those based on the Krylov subspace. Since the orthogonalization cost and memory requirement can quickly become overwhelming as the basis grows, the Krylov method is often restarted after a few iterations. This paper proposes a new acceleration technique for restarted Krylov methods based on randomization. The numerical experiments show that the randomized method greatly outperforms the classical approach with the same level of accuracy. In fact, randomization can actually improve the convergence rate of restarted methods in some cases. The paper also compares the performance and stability of the randomized methods proposed so far for solving very large ill-conditioned problems, complementing the numerical analyses from previous studies.
format Preprint
id arxiv_https___arxiv_org_abs_2503_22631
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Accelerating a restarted Krylov method for matrix functions with randomization
Guidotti, Nicolas L.
Martinsson, Per-Gunnar
Acebrón, Juan A.
Monteiro, José
Numerical Analysis
68W20, 65F60, 65F50, 65M20
Many scientific applications require the evaluation of the action of the matrix function over a vector and the most common methods for this task are those based on the Krylov subspace. Since the orthogonalization cost and memory requirement can quickly become overwhelming as the basis grows, the Krylov method is often restarted after a few iterations. This paper proposes a new acceleration technique for restarted Krylov methods based on randomization. The numerical experiments show that the randomized method greatly outperforms the classical approach with the same level of accuracy. In fact, randomization can actually improve the convergence rate of restarted methods in some cases. The paper also compares the performance and stability of the randomized methods proposed so far for solving very large ill-conditioned problems, complementing the numerical analyses from previous studies.
title Accelerating a restarted Krylov method for matrix functions with randomization
topic Numerical Analysis
68W20, 65F60, 65F50, 65M20
url https://arxiv.org/abs/2503.22631