We consider solving partial differential equations (PDEs) with Fourier neural operators (FNOs), which operate in the frequency domain. Since the laws of physics do not depend on the coordinate system used to describe them, it is desirable to encode such symmetries in the neural operator architecture for better performance and easier learning. While encoding symmetries in the physical domain using group theory has been studied extensively, how to capture symmetries in the frequency domain is under-explored. In this work, we extend group convolutions to the frequency domain and design Fourier layers that are equivariant to rotations, translations, and reflections by leveraging the equivariance property of the Fourier transform. The resulting $G$-FNO architecture generalizes well across input resolutions and performs well in settings with varying levels of symmetry. Our code is publicly available as part of the AIRS library (https://github.com/divelab/AIRS).

本研究旨在通过傅里叶神经算子来求解偏微分方程，从而将对称性编码到神经算子中以获得更好的性能和更容易的学习，通过将群卷积扩展到频域并设计傅里叶层使其在旋转、平移和反射等变换下等变，从而实现了广义的G-FNO体系结构。

群等变傅里叶神经算子用于偏微分方程