HYPERION: Fine-Grained Hypersphere Alignment for Robust Federated Graph Learning - Wan, Frank; Shang, Xiaoran; Wu, Yuxin; Zhang, Guibin; Bi, Jinhe; Zheng, Liangtao; Lin, Xin; Liu, Yue; Ma, Yanbiao; Huang, Wenke; Du, Bo (Advances in Neural Information Processing Systems, 2025)