Sparse Attention Adaptation for Long Reasoning - Gao, Yizhao; Guo, Shuming; Cao, Shijie; Xia, Yuqing; Cheng, Yu; Wang, Lei; Ma, Lingxiao; Sun, Yutao; Ye, Tianzhu; Dong, Li; So, Hayden; Hua, Yu; et al. (International Conference on Learning Representations, 2026)