Leveraging Pretrained Language Models as Energy Functions for Glauber Dynamics Text Diffusion

Tarun Kathuria, Sachin Kumar


Abstract
We present a discrete diffusion-based generative model for text generation using Glauber dynamics from statistical physics. Our main insight is that instead of trying to train a discrete state space diffusion model using Glauber dynamics with a uniform transition kernel as the forward process, one can set up an “energy function” based on pretrained causal/masked language models, which, when viewed as the stationary distribution, allows us to significantly improve the quality of the generated text. Using UL2 as our pretrained models and modifying and incorporating it into our diffusion pipeline, we obtain significantly better perplexities than prior diffusion-based text generative models and are competitive with the perplexities of GPT-2-medium and GPT-2-large for comparable model sizes. Furthermore, our models outperform prior diffusion models and GPT-2 style auto-regressive models on some zero-shot common sense reasoning tasks as well as some planning/search tasks.
Anthology ID:
2026.findings-acl.2117
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
42625–42643
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2117/
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Cite (ACL):
Tarun Kathuria and Sachin Kumar. 2026. Leveraging Pretrained Language Models as Energy Functions for Glauber Dynamics Text Diffusion. In Findings of the Association for Computational Linguistics: ACL 2026, pages 42625–42643, San Diego, California, United States. Association for Computational Linguistics.
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Leveraging Pretrained Language Models as Energy Functions for Glauber Dynamics Text Diffusion (Kathuria & Kumar, Findings 2026)
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