Rejuvenating AMLI-Cycle: From Chebyshev Polynomials to Momentum Acceleration

Fuente: arXiv
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Autori principali: Niu, Chunyan, He, Yunhui, Hu, Xiaozhe
Natura: Preprint
Pubblicazione: 2020
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author Niu, Chunyan
He, Yunhui
Hu, Xiaozhe
author_facet Niu, Chunyan
He, Yunhui
Hu, Xiaozhe
contents In this paper, we investigate the AMLI-cycle method and make two contributions. First, we revisit the AMLI-cycle using the Chebyshev polynomials and establish a theory for its uniform convergence, assuming the two-grid method converges uniformly. This removes the need for estimating extreme eigenvalues at all coarse levels. Only an estimation of the two-grid convergence rate is needed, which could be done on the second coarsest level, simplifying implementation and reducing computational costs for large-scale problems. Second, we introduce a momentum-accelerated AMLI-cycle using polynomials from momentum accelerations. This novel approach ensures a uniform condition number without requiring extreme eigenvalue or two-grid convergence rate estimations, making its implementation as straightforward as standard multigrid methods. We prove that it is asymptotically as good as the AMLI-cycle using the Chebyshev polynomials when the quadratic momentum-accelerated polynomials is used. Numerical experiments confirm the robustness and efficiency of the momentum-accelerated AMLI-cycle across various problems, demonstrating performance comparable to the Chebyshev-based AMLI-cycle. These findings validate the theoretical advantages and practical efficacy of the momentum-accelerated AMLI-cycle.
format Preprint
id arxiv_https___arxiv_org_abs_2006_16986
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle Rejuvenating AMLI-Cycle: From Chebyshev Polynomials to Momentum Acceleration
Niu, Chunyan
He, Yunhui
Hu, Xiaozhe
Numerical Analysis
65N55, 65F08, 65F10, 65B99
In this paper, we investigate the AMLI-cycle method and make two contributions. First, we revisit the AMLI-cycle using the Chebyshev polynomials and establish a theory for its uniform convergence, assuming the two-grid method converges uniformly. This removes the need for estimating extreme eigenvalues at all coarse levels. Only an estimation of the two-grid convergence rate is needed, which could be done on the second coarsest level, simplifying implementation and reducing computational costs for large-scale problems. Second, we introduce a momentum-accelerated AMLI-cycle using polynomials from momentum accelerations. This novel approach ensures a uniform condition number without requiring extreme eigenvalue or two-grid convergence rate estimations, making its implementation as straightforward as standard multigrid methods. We prove that it is asymptotically as good as the AMLI-cycle using the Chebyshev polynomials when the quadratic momentum-accelerated polynomials is used. Numerical experiments confirm the robustness and efficiency of the momentum-accelerated AMLI-cycle across various problems, demonstrating performance comparable to the Chebyshev-based AMLI-cycle. These findings validate the theoretical advantages and practical efficacy of the momentum-accelerated AMLI-cycle.
title Rejuvenating AMLI-Cycle: From Chebyshev Polynomials to Momentum Acceleration
topic Numerical Analysis
65N55, 65F08, 65F10, 65B99
url https://arxiv.org/abs/2006.16986