Beyond Real: Imaginary Extension of Rotary Position Embeddings for Long-Context LLMs - Liu, Xiaoran; Song, Yuerong; Liu, Zhigeng; Huang, Zengfeng; Guo, Qipeng; Liu, Zhaoxiang; Lian, Shiguo; He, Ziwei; Qiu, Xipeng (International Conference on Learning Representations, 2026)