TY - JOUR T1 - A Reduced Order Schwarz Method for Nonlinear Multiscale Elliptic Equations Based on Two-Layer Neural Networks AU - Chen , Shi AU - Ding , Zhiyan AU - Li , Qin AU - Wright , Stephen J. JO - Journal of Computational Mathematics VL - 2 SP - 570 EP - 596 PY - 2024 DA - 2024/01 SN - 42 DO - http://doi.org/10.4208/jcm.2204-m2021-0311 UR - https://global-sci.org/intro/article_detail/jcm/22892.html KW - Nonlinear homogenization, Multiscale elliptic problem, Neural networks, Domain decomposition. AB -

Neural networks are powerful tools for approximating high dimensional data that have been used in many contexts, including solution of partial differential equations (PDEs). We describe a solver for multiscale fully nonlinear elliptic equations that makes use of domain decomposition, an accelerated Schwarz framework, and two-layer neural networks to approximate the boundary-to-boundary map for the subdomains, which is the key step in the Schwarz procedure. Conventionally, the boundary-to-boundary map requires solution of boundary-value elliptic problems on each subdomain. By leveraging the compressibility of multiscale problems, our approach trains the neural network offline to serve as a surrogate for the usual implementation of the boundary-to-boundary map. Our method is applied to a multiscale semilinear elliptic equation and a multiscale $p$-Laplace equation. In both cases we demonstrate significant improvement in efficiency as well as good accuracy and generalization performance.