PEAR: Permutation-Equivariant Adaptive Routing Multi-Agent Debate

Yang Feng, Ziwei Xu, Xia Hu, Fengxiang He


Abstract
Multi-agent debate improves the reliability of large language models (LLMs) through iterative peer critiques. However, fixed topologies often introduce persistent positional biases, amplify unreliable agents, and cause high sensitivity to role assignments. We introduce Permutation-Equivariant Adaptive Routing Multi-Agent Debate (PEAR), an inference-time protocol that dynamically reconfigures communication roles and sparse topologies across consecutive debate rounds. By strategically switching agent-to-role assignments based on evolving agent states, PEAR prevents any agent from permanently occupying a privileged network position or distributes influence more evenly across the debate. We theoretically characterize PEAR as an equivariant sparse router: it preserves accuracy under agent relabeling while reducing routing complexity and improving generalization. Comprehensive empirical evaluations across four reasoning benchmarks and six diverse LLM backbones demonstrate PEAR significantly improves average accuracy over the strongest debate baselines. The code is at https://github.com/EVIEHub/PEAR.
Anthology ID:
2026.emnlp-main.2114
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
48076–48103
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2114/
DOI:
Bibkey:
Cite (ACL):
Yang Feng, Ziwei Xu, Xia Hu, and Fengxiang He. 2026. PEAR: Permutation-Equivariant Adaptive Routing Multi-Agent Debate. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 48076–48103, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PEAR: Permutation-Equivariant Adaptive Routing Multi-Agent Debate (Feng et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.2114.pdf