Decoupling scales via localized subspace iteration and temporal splitting for multiscale parabolic equations

Fuente: arXiv
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Main Authors: Chung, Eric T., Jiang, Lijian, Li, Mengnan, Wang, Yajun
Format: Preprint
Published: 2026
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_version_ 1866917475419947008
author Chung, Eric T.
Jiang, Lijian
Li, Mengnan
Wang, Yajun
author_facet Chung, Eric T.
Jiang, Lijian
Li, Mengnan
Wang, Yajun
contents Simulating diffusion in heterogeneous media presents a significant computational challenge, as resolving microscopic physical scales traditionally demands excessively fine computational grids. To overcome this barrier, we extend the Localized Subspace Iteration (LSI) framework to multiscale parabolic equations. The proposed method constructs optimal, low-dimensional trial spaces by iteratively approximating the dominant eigenspaces of local inverse operators via Localized Standard Subspace Iteration (LSSI) or Localized Krylov Subspace Iteration (LKSI). Because these LSI basis functions are inherently tailored to capture the slow-decaying, low-frequency modes of the parabolic solution, they naturally suppress error accumulation over long-term integration. To further improve computational efficiency, we decouple the basis construction into an offline phase and implement a contrast-independent, partially explicit temporal splitting scheme for online time-stepping. By explicitly advancing the dominant macroscopic modes while implicitly treating high-frequency microscopic corrections, this scheme guarantees stability without imposing restrictive time-step constraints. We establish rigorous a priori error estimates in both the energy and $L^2$ norms. Numerical experiments illustrate the accuracy and efficiency of the LSI framework, particularly highlighting the LKSI method's advantages in handling high-contrast, complex multiscale media.
format Preprint
id arxiv_https___arxiv_org_abs_2605_08634
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Decoupling scales via localized subspace iteration and temporal splitting for multiscale parabolic equations
Chung, Eric T.
Jiang, Lijian
Li, Mengnan
Wang, Yajun
Numerical Analysis
65M60, 65N30, 35B27
Simulating diffusion in heterogeneous media presents a significant computational challenge, as resolving microscopic physical scales traditionally demands excessively fine computational grids. To overcome this barrier, we extend the Localized Subspace Iteration (LSI) framework to multiscale parabolic equations. The proposed method constructs optimal, low-dimensional trial spaces by iteratively approximating the dominant eigenspaces of local inverse operators via Localized Standard Subspace Iteration (LSSI) or Localized Krylov Subspace Iteration (LKSI). Because these LSI basis functions are inherently tailored to capture the slow-decaying, low-frequency modes of the parabolic solution, they naturally suppress error accumulation over long-term integration. To further improve computational efficiency, we decouple the basis construction into an offline phase and implement a contrast-independent, partially explicit temporal splitting scheme for online time-stepping. By explicitly advancing the dominant macroscopic modes while implicitly treating high-frequency microscopic corrections, this scheme guarantees stability without imposing restrictive time-step constraints. We establish rigorous a priori error estimates in both the energy and $L^2$ norms. Numerical experiments illustrate the accuracy and efficiency of the LSI framework, particularly highlighting the LKSI method's advantages in handling high-contrast, complex multiscale media.
title Decoupling scales via localized subspace iteration and temporal splitting for multiscale parabolic equations
topic Numerical Analysis
65M60, 65N30, 35B27
url https://arxiv.org/abs/2605.08634