On the forefront of scientific computing, Deep Learning (DL), i.e., machine learning with Deep Neural Networks (DNNs), has emerged a powerful new tool for solving Partial Differential Equations (PDEs). It has been observed that DNNs are particularly well suited to weakening the effect of the curse of dimensionality, a term coined by Richard E. Bellman in the late `50s to describe challenges such as the exponential dependence of the sample complexity, i.e., the number of samples required to solve an approximation problem, on the dimension of the ambient space. However, although DNNs have been used to solve PDEs since the `90s, the literature underpinning their mathematical efficiency in terms of numerical analysis (i.e., stability, accuracy, and sample complexity), is only recently beginning to emerge. In this paper, we leverage recent advancements in function approximation using sparsity-based techniques and random sampling to develop and analyze an efficient high-dimensional PDE solver based on DL. We show, both theoretically and numerically, that it can compete with a novel stable and accurate compressive spectral collocation method. In particular, we demonstrate a new practical existence theorem, which establishes the existence of a class of trainable DNNs with suitable bounds on the network architecture and a sufficient condition on the sample complexity, with logarithmic or, at worst, linear scaling in dimension, such that the resulting networks stably and accurately approximate a diffusion-reaction PDE with high probability.

利用稀疏技术和随机采样的最新进展，本研究基于深度学习开发和分析了一个高维偏微分方程求解器，理论和数值结果表明其在稳定性和准确性方面可以与一个新型的压缩谱逼近方法竞争，并证明了存在一类可训练的深度神经网络，具有适当的网络结构和样本复杂度的充分条件，并以对数或最坏情况下的线性扩展在维度上稳定且准确地逼近扩散-反应型偏微分方程的高概率。

Physics-informed deep learning and compressive collocation for
  high-dimensional diffusion-reaction equations: practical existence theory and
  numerics

基于物理信息的深度学习和压缩选点法，高维扩散反应方程的实际存在理论和数值计算