LoRi: Low-Rank Distillation for Implicit Reasoning

Ryan Solgi, Jiayi Tian, Zheng Zhang


Abstract
Implicit chain-of-thought (iCoT) methods aim to internalize reasoning in large language models, but often underperform explicit CoT prompting. We empirically find that hidden-state reasoning trajectories exhibit low-rank structure. Motivated by this observation, we propose a low-rank distillation framework that transfers reasoning by aligning teacher and student trajectories in a shared low-rank tensor subspace using first- and second-order statistics. The resulting formulation captures the global structure of reasoning while supporting a compact latent reasoning process. We evaluate the method across multiple model families, including LLaMA and Qwen, at different scales on mathematical reasoning benchmarks. Our approach consistently improves performance, especially on challenging multi-step tasks, approaching explicit CoT accuracy and outperforming prior iCoT distillation methods.
Anthology ID:
2026.findings-emnlp.2322
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
49860–49871
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2322/
DOI:
10.18653/2026.findings-emnlp.2322
Bibkey:
Cite (ACL):
Ryan Solgi, Jiayi Tian, and Zheng Zhang. 2026. LoRi: Low-Rank Distillation for Implicit Reasoning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 49860–49871, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
LoRi: Low-Rank Distillation for Implicit Reasoning (Solgi et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2322.pdf