Best approximation results and essential boundary conditions for novel types of weak adversarial network discretizations for PDEs

Fuente: arXiv
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Main Authors: Bertoluzza, Silvia, Burman, Erik, He, Cuiyu
Format: Preprint
Published: 2023
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author Bertoluzza, Silvia
Burman, Erik
He, Cuiyu
author_facet Bertoluzza, Silvia
Burman, Erik
He, Cuiyu
contents In this paper, we provide a theoretical analysis of the recently introduced weakly adversarial networks (WAN) method, used to approximate partial differential equations in high dimensions. We address the existence and stability of the solution, as well as approximation bounds. More precisely, we prove the existence of discrete solutions, intended in a suitable weak sense, for which we prove a quasi-best approximation estimate similar to Cea's lemma, a result commonly found in finite element methods. We also propose two new stabilized WAN-based formulas that avoid the need for direct normalization. Furthermore, we analyze the method's effectiveness for the Dirichlet boundary problem that employs the implicit representation of the geometry. The key requirement for achieving the best approximation outcome is to ensure that the space for the test network satisfies a specific condition, known as the inf-sup condition, essentially requiring that the test network set is sufficiently large when compared to the trial space. The method's accuracy, however, is only determined by the space of the trial network. We also devise a pseudo-time XNODE neural network class for static PDE problems, yielding significantly faster convergence results than the classical DNN network.
format Preprint
id arxiv_https___arxiv_org_abs_2307_05012
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Best approximation results and essential boundary conditions for novel types of weak adversarial network discretizations for PDEs
Bertoluzza, Silvia
Burman, Erik
He, Cuiyu
Numerical Analysis
65M12, 65N12
In this paper, we provide a theoretical analysis of the recently introduced weakly adversarial networks (WAN) method, used to approximate partial differential equations in high dimensions. We address the existence and stability of the solution, as well as approximation bounds. More precisely, we prove the existence of discrete solutions, intended in a suitable weak sense, for which we prove a quasi-best approximation estimate similar to Cea's lemma, a result commonly found in finite element methods. We also propose two new stabilized WAN-based formulas that avoid the need for direct normalization. Furthermore, we analyze the method's effectiveness for the Dirichlet boundary problem that employs the implicit representation of the geometry. The key requirement for achieving the best approximation outcome is to ensure that the space for the test network satisfies a specific condition, known as the inf-sup condition, essentially requiring that the test network set is sufficiently large when compared to the trial space. The method's accuracy, however, is only determined by the space of the trial network. We also devise a pseudo-time XNODE neural network class for static PDE problems, yielding significantly faster convergence results than the classical DNN network.
title Best approximation results and essential boundary conditions for novel types of weak adversarial network discretizations for PDEs
topic Numerical Analysis
65M12, 65N12
url https://arxiv.org/abs/2307.05012