Hyperbolic space is emerging as a promising learning space for representation learning, owning to its exponential growth volume. Compared with the flat Euclidean space, the curved hyperbolic space is far more ambient and embeddable, particularly for datasets with implicit tree-like architectures, such as hierarchies and power-law distributions. On the other hand, the structure of a real-world network is usually intricate, with some regions being tree-like, some being flat, and others being circular. Directly embedding heterogeneous structural networks into a homogeneous embedding space unavoidably brings inductive biases and distortions. Inspiringly, the discrete curvature can well describe the local structure of a node and its surroundings, which motivates us to investigate the information conveyed by the network topology explicitly in improving geometric learning. To this end, we explore the properties of the local discrete curvature of graph topology and the continuous global curvature of embedding space. Besides, a Hyperbolic Curvature-aware Graph Neural Network, HCGNN, is further proposed. In particular, HCGNN utilizes the discrete curvature to lead message passing of the surroundings and adaptively adjust the continuous curvature simultaneously. Extensive experiments on node classification and link prediction tasks show that the proposed method outperforms various competitive models by a large margin in both high and low hyperbolic graph data. Case studies further illustrate the efficacy of discrete curvature in finding local clusters and alleviating the distortion caused by hyperbolic geometry.

本研究探索图形拓扑的离散曲率和嵌入空间的连续全局曲率的属性，提出了一种基于超边曲率感知的图神经网络（HCGNN），该网络利用离散曲率引导周围消息传递，并同时自适应调整连续曲率。在节点分类和链接预测任务上进行了广泛的实验，结果表明所提出的方法在高超曲线图数据和低超曲线图数据中均优于各种竞争模型。案例研究进一步证明了离散曲率在发现本地集群和缓解超曲线几何引起的畸变方面的有效性。

双曲曲率图神经网络