Neural Green's Function Accelerated Iterative Methods for Solving Indefinite Boundary Value Problems

Fuente: arXiv
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Autores principales: Li, Shengyan, Sun, Qi, Xu, Xuejun, Zheng, Bowen
Formato: Preprint
Publicado: 2024
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author Li, Shengyan
Sun, Qi
Xu, Xuejun
Zheng, Bowen
author_facet Li, Shengyan
Sun, Qi
Xu, Xuejun
Zheng, Bowen
contents Neural operators, which learn mappings between the function spaces, have been applied to solve boundary value problems in various ways, including learning mappings from the space of the forcing terms to the space of the solutions with the substantial requirements of data pairs. In this work, we present a data-free neural operator integrated with physics, which learns the Green kernel directly. Our method proceeds in three steps: 1. The governing equations for the Green's function are reformulated into an interface problem, where the delta Dirac function is removed; 2. The interface problem is embedded in a lifted space of higher-dimension to handle the jump in the derivative, but still solved on a two-dimensional surface without additional sampling cost; 3. Deep neural networks are employed to address the curse of dimensionality caused by this lifting operation. The approximate Green's function obtained through our approach is then used to construct preconditioners for the linear systems allowed by its mathematical properties. Furthermore, the spectral bias of it revealed through both theoretical analysis and numerical validation contrasts with the smoothing effects of traditional iterative solvers, which motivates us to propose a hybrid iterative method that combines these two solvers. Numerical experiments demonstrate the effectiveness of our approximate Green's function in accelerating iterative methods, proving fast convergence for solving indefinite problems even involving discontinuous coefficients.
format Preprint
id arxiv_https___arxiv_org_abs_2410_06919
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Neural Green's Function Accelerated Iterative Methods for Solving Indefinite Boundary Value Problems
Li, Shengyan
Sun, Qi
Xu, Xuejun
Zheng, Bowen
Numerical Analysis
Neural operators, which learn mappings between the function spaces, have been applied to solve boundary value problems in various ways, including learning mappings from the space of the forcing terms to the space of the solutions with the substantial requirements of data pairs. In this work, we present a data-free neural operator integrated with physics, which learns the Green kernel directly. Our method proceeds in three steps: 1. The governing equations for the Green's function are reformulated into an interface problem, where the delta Dirac function is removed; 2. The interface problem is embedded in a lifted space of higher-dimension to handle the jump in the derivative, but still solved on a two-dimensional surface without additional sampling cost; 3. Deep neural networks are employed to address the curse of dimensionality caused by this lifting operation. The approximate Green's function obtained through our approach is then used to construct preconditioners for the linear systems allowed by its mathematical properties. Furthermore, the spectral bias of it revealed through both theoretical analysis and numerical validation contrasts with the smoothing effects of traditional iterative solvers, which motivates us to propose a hybrid iterative method that combines these two solvers. Numerical experiments demonstrate the effectiveness of our approximate Green's function in accelerating iterative methods, proving fast convergence for solving indefinite problems even involving discontinuous coefficients.
title Neural Green's Function Accelerated Iterative Methods for Solving Indefinite Boundary Value Problems
topic Numerical Analysis
url https://arxiv.org/abs/2410.06919