Interest has been rising lately towards methods representing data in non-Euclidean spaces, e.g. hyperbolic or spherical, that provide specific inductive biases useful for certain real-world data properties, e.g. scale-free, hierarchical or cyclical. However, the popular graph neural networks are currently limited in modeling data only via Euclidean geometry and associated vector space operations. Here, we bridge this gap by proposing mathematically grounded generalizations of graph convolutional networks (GCN) to (products of) constant curvature spaces. We do this by i) introducing a unified formalism that can interpolate smoothly between all geometries of constant curvature, ii) leveraging gyro-barycentric coordinates that generalize the classic Euclidean concept of the center of mass. Our class of models smoothly recover their Euclidean counterparts when the curvature goes to zero from either side. Empirically, we outperform Euclidean GCNs in the tasks of node classification and distortion minimization for symbolic data exhibiting non-Euclidean behavior, according to their discrete curvature.

本文介绍了一种通过使用（产品）恒定曲率空间的图神经网络的数学基础来建模非欧几里德几何的方法，并利用类欧几里得的重心坐标来扩展了图卷积网络，实现了对特定真实世界数据特性（例如无标度、分层或循环）的归纳偏差，经实验证明，在符号数据的节点分类和畸变最小化任务中，我们的方法比欧几里得图卷积网络表现出更好的性能。

常曲率图卷积网络