@article{beyondgrpoandonpolicydistillationanempir,
  title = {Beyond GRPO and On-Policy Distillation: An Empirical Sparse-to-Dense Reward Principle for Language-Model Post-Training},
  author = {Yuanda Xu and Hejian Sang and Zhengze Zhou and Ran He and Zhipeng Wang and Alborz Geramifard},
  year = {2026},
  eprint = {2605.12483},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.12483},
}