@article{whenandwhygroupingattentionheadsaccelera,
  title = {When and Why Grouping Attention Heads Accelerates Muon Optimization},
  author = {Hongtao Zhang and Wenjie Zhou and Wei Chen and Xueqi Cheng},
  year = {2026},
  eprint = {2605.08933},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.08933},
}