ArenaRL: Scaling RL for Open-Ended Agents via Tournament-based Relative Ranking. - Qiang Zhang 051; Boli Chen; Fanrui Zhang; Ruixue Ding; Shihang Wang; Qiuchen Wang; Yinfeng Huang; Haonan Zhang; Rongxiang Zhu; Pengyong Wang; Ailin Ren; Xin Li 144; et al. (CoRR, 2026)