We introduce physics informed neural networks -- neural networks that are trained to solve supervised learning tasks while respecting any given law of physics described by general nonlinear partial differential equations. In this second part of our two-part treatise, we focus on the problem of data-driven discovery of partial differential equations. Depending on whether the available data is scattered in space-time or arranged in fixed temporal snapshots, we introduce two main classes of algorithms, namely continuous time and discrete time models. The effectiveness of our approach is demonstrated using a wide range of benchmark problems in mathematical physics, including conservation laws, incompressible fluid flow, and the propagation of nonlinear shallow-water waves.

本文介绍了物理知识启发的神经网络，依据偏微分方程描述的物理学定律进行训练。本文第二部分聚焦于基于数据驱动的偏微分方程发现问题，并介绍了两类算法，即连续时间和离散时间模型。本方法在包括守恒定理、不可压缩流体流动和非线性浅水波传播等多个数学物理基准问题上的有效性得到了证明。

物理知识指导的深度学习（第二部分）：基于数据发现非线性偏微分方程