SoLoPO: Unlocking Long-Context Capabilities in LLMs via Short-to-Long Preference Optimization - Sun, Huashan; Liao, Shengyi; Han, Yansen; Bai, Yu; Gao, Yang; Fu, Cheng; Shen, Weizhou; Wan, Fanqi; Yan, Ming; Zhang, Ji; Huang, Fei (International Conference on Learning Representations, 2026)