Score-Based Generative Modeling without Diffusion: Langevin MCMC All the Way

Score-Based Generative Modeling without Diffusion: Langevin MCMC All the Way

🎙 Saeed Saremi 👥 75K 📅 August 7, 2026 ⏱ 52 min 👁 421 📄 expert opinion 🧭 2026-08-08
Available in: English (current) Français

Keywords

score functionLangevin dynamicsempirical Bayesdenoisinglog-concave sampling

Summary

Saeed Saremi presents an alternative to standard diffusion models for generative modeling, based on Langevin MCMC at a fixed noise level. He starts with a historical overview, highlighting Herbert Robbins’ empirical Bayes framework and its connection to score functions. He explains the Tweedie formula and how it leads to learning the score of noisy data. The key idea is to add noise to clean data, learn the score of the noisy distribution, and then sample using Langevin dynamics, followed by a denoising step (walk-jump sampling). He emphasizes that this approach avoids the need for a time-varying diffusion process and can be framed as log-concave sampling when the noise level is chosen appropriately. He also discusses extensions to discrete data. The talk is conceptual, with limited empirical results, but provides a rigorous theoretical foundation.

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Critical Evaluation

The talk provides a compelling and rigorous theoretical perspective on generative modeling, challenging the dominant diffusion-based paradigm. Saremi’s argument is well-structured, starting from foundational work by Robbins and connecting it to modern score-based methods. The mathematical derivations are clear, and he addresses audience questions effectively. However, the talk is largely conceptual, with little empirical validation presented. The claim that the problem is ‘cracked’ is optimistic, as practical challenges remain, such as scalability and sample quality. The sources cited are primarily historical and the speaker’s own work, which may limit the breadth of perspectives. The title accurately reflects the content, and the talk is suitable for a specialized audience. Overall, it is a valuable contribution to the field, offering a fresh angle on generative modeling.

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Title / Content Match

The title accurately reflects the content, focusing on score-based generative modeling using Langevin MCMC without diffusion.

Quality & Reliability

8/10

The talk is given by a researcher at Genentech with a strong background in the field, presenting a coherent theoretical framework. The content is based on published work and includes mathematical derivations, but it is a single perspective and not peer-reviewed in this format.

Key Moments

Cited Sources

Concurring Sources

  • Robbins, H. (1956). An Empirical Bayes Approach to Statistics — Foundational paper on empirical Bayes, cited in the talk.
  • Miyazawa, K. (1961). An empirical Bayes estimator for the mean of a normal population — Original derivation of the Tweedie formula, mentioned in the talk.

Dissenting Sources

Contribution & Novelties

The talk presents a novel framework for generative modeling that avoids the time-varying diffusion process, instead using Langevin MCMC at a fixed noise level. This simplifies the theoretical analysis and connects to classical empirical Bayes. The idea of reducing effective noise through accumulation of noisy measurements is a fresh perspective. The extension to discrete data is also a contribution.

Pour aller plus loin :

87 words

Radar Profile

The radar profile shows high scores in technical level and information quality, indicating a technically rigorous talk. The lower score in information quantity reflects the conceptual focus with limited empirical results. Overall, it is a specialized presentation for an expert audience.

Reliability 8/10