MM-HELIX: Boosting Multimodal Long-Chain Reflective Reasoning with Holistic Platform and Adaptive Hybrid Policy Optimization - Zhao, Xiangyu; Lin, Lin; Liang, Tianhao; Zhou, Yifan; Chai, Wenhao; Gu, Yuzhe; Wang, Weiyun; Chen, Kai; Luo, Gen; Yan, Junchi; Zhang, Wenwei; Yang, Hua; et al. (International Conference on Learning Representations, 2026)