Perplexity Trap: PLM-Based Retrievers Overrate Low Perplexity Documents - Wang, Haoyu; Dai, Sunhao; Zhao, Haiyuan; Pang, Liang; Zhang, Xiao; Wang, Gang; Dong, Zhenhua; Xu, Jun; Wen, Ji-Rong (International Conference on Learning Representations, 2025)