论文标题
在科学机器学习中执行确切的物理学:图形上的数据驱动的外观演算
Enforcing exact physics in scientific machine learning: a data-driven exterior calculus on graphs
论文作者
论文摘要
随着传统的机器学习工具越来越多地应用于科学和工程应用程序,物理知识的方法已成为有效的工具,可以使推断具有对物理可实现性必不可少的属性的推论。在有希望的同时,这些方法通常通过惩罚来弱执行物理。为了强烈执行物理,我们转向基于组合霍奇理论和物理兼容的偏微分方程(PDE)的外部演算框架。从历史上看,这两个领域在很大程度上仍然很明显,因为图是严格的拓扑对象,缺少PDE离散化基础的度量信息。我们提出了一种方法,可以将这些缺失的度量信息从数据中学到,将图作为粗粒网状替代物,从组合霍奇理论中继承了理想的保护和精确的序列结构。所得的数据驱动的外部演算(DDEC)可用于提取具有良好功能良好的数学保证的构造结构的替代模型。该方法承认了PDE受限的优化培训策略,该策略可以保证机器学习的模型即使是训练有素的模型或小型数据制度,也可以强制实施物理学的精确度。我们提供了一类模型的方法分析,该模型旨在重现椭圆问题的非线性扰动,并提供了代表地下流和电磁学代表的学习$ H(div)/h(div)/h(curl)$系统。
As traditional machine learning tools are increasingly applied to science and engineering applications, physics-informed methods have emerged as effective tools for endowing inferences with properties essential for physical realizability. While promising, these methods generally enforce physics weakly via penalization. To enforce physics strongly, we turn to the exterior calculus framework underpinning combinatorial Hodge theory and physics-compatible discretization of partial differential equations (PDEs). Historically, these two fields have remained largely distinct, as graphs are strictly topological objects lacking the metric information fundamental to PDE discretization. We present an approach where this missing metric information may be learned from data, using graphs as coarse-grained mesh surrogates that inherit desirable conservation and exact sequence structure from the combinatorial Hodge theory. The resulting data-driven exterior calculus (DDEC) may be used to extract structure-preserving surrogate models with mathematical guarantees of well-posedness. The approach admits a PDE-constrained optimization training strategy which guarantees machine-learned models enforce physics to machine precision, even for poorly trained models or small data regimes. We provide analysis of the method for a class of models designed to reproduce nonlinear perturbations of elliptic problems and provide examples of learning $H(div)/H(curl)$ systems representative of subsurface flows and electromagnetics.