Domain Decomposition Subspace Neural Network Method for Solving Linear and Nonlinear Partial Differential Equations
Zhenxing Fu, Hongliang Liu, Zhiqiang Sheng, Baixue Xing
TL;DR
The paper presents the Domain Decomposition Subspace Neural Network (DD-SNN) method, which integrates domain decomposition with subspace neural networks to solve linear and nonlinear PDEs. Local neural solvers construct basis functions in subspaces, while $C^k$ continuity at interfaces ensures a smooth global solution; nonlinear problems are tackled via Picard and Newton iterations. Across diverse linear and nonlinear tests (Helmholtz, Poisson, parabolic, boundary-layer, Burgers), DD-SNN achieves markedly higher accuracy (often reaching $ orm{e}_{L^2}$ on the order of $10^{-10}$ to $10^{-12}$) with substantially lower training costs than PINNs, LocELM, SNN, ELM, DGM, and DRM. The approach enables parallelizable local training, reduces optimization complexity, and demonstrates strong performance on challenging multiscale and boundary-layer problems, indicating significant practical impact for scalable PDE solvers.
Abstract
This paper proposes a domain decomposition subspace neural network method for efficiently solving linear and nonlinear partial differential equations. By combining the principles of domain decomposition and subspace neural networks, the method constructs basis functions using neural networks to approximate PDE solutions. It imposes $C^k$ continuity conditions at the interface of subdomains, ensuring smoothness across the global solution. Nonlinear PDEs are solved using Picard and Newton iterations, analogous to classical methods. Numerical experiments demonstrate that our method achieves exceptionally high accuracy, with errors reaching up to $10^{-13}$, while significantly reducing computational costs compared to existing approaches, including PINNs, DGM, DRM. The results highlight the method's superior accuracy and training efficiency.
