Discrete Diffusion Reading Group

Exploring diffusion-based generative models on discrete spaces.

Meeting at 1pm ET / 10am PT / 7pm CET / 10:30pm IST on Mondays.

Latest Sessions

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S35 | SOL: Measuring Gaps between Text Distributions
53:44
October 26, 2026

S35 | SOL: Measuring Gaps between Text Distributions

Gregor Kornhardt presents SOL, a distance between text distributions for evaluating diffusion and flow-based language models, which only provide likelihood bounds of varying tightness. SOL represents each sequence by the empirical measure of its hidden states under a fixed transformer and compares the distributions of these measures with the double sliced Wasserstein distance, which the authors prove is a metric when the transformer is injective. SOL detects distributional failures, recovers expected model trends, and gives stable sample-based estimates.

S34 | Simplex Diffusion Models
1:08:44
October 19, 2026

S34 | Simplex Diffusion Models

Justin Deschenaux presents Simplex Diffusion Models, which lift the diffusion process to the probability simplex so that beliefs over categories carry across denoising steps instead of collapsing through categorical sampling. SDMs have closed-form reverse transitions, train with a simple cross-entropy loss, and use a DDIM-like sampler with tunable stochasticity. They are competitive with strong discrete diffusion baselines on OpenWebText, beat masked and uniform diffusion on code generation, and, distilled to 8 steps, solve more GSM8K problems than distilled discrete diffusion models using 128 steps.

S33 | Distilling Autoregressive Models into One-step Flow Maps
53:55
October 12, 2026

S33 | Distilling Autoregressive Models into One-step Flow Maps

Yeongmin Kim presents Gumbel Straight Flow, a continuous flow map language model that leverages the noise-data coupling of a pretrained autoregressive model. The authors show theoretically that the coupling between Gumbel noise and one-hot token sequences induced by an autoregressive model yields non-intersecting linear paths connecting the noise to the sequence representations, which is what makes few-step sampling tractable. GSF is trained with a flow map semigroup objective whose tangent condition is guided directly by the AR teacher, and it outperforms current few-step language generation baselines across pretraining and downstream benchmarks.

Featured Videos

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How did diffusion LLMs get so fast?
22:14
February 9, 2026

How did diffusion LLMs get so fast?

Techniques for accelerating diffusion LLMs, from self-distillation and curriculum learning to KV caching and block diffusion

But How Do Diffusion Language Models Actually Work?
12:27
August 3, 2025

But How Do Diffusion Language Models Actually Work?

Jia-Bin Huang explores several ideas for applying diffusion models to language modeling

Simple Diffusion Language Models
15:07
July 3, 2024

Simple Diffusion Language Models

Quick introduction to Masked Diffusion Language Models (MDLM) by Alexander Rush

About the Reading Group

Diffusion LLMs are faster, more controllable successors to traditional LLMs and are rapidly gaining adoption. This reading group builds a community for exchanging and debating emerging ideas in this space. While our primary focus is discrete diffusion models for language, we also welcome work on other modalities and applications, such as molecular design, drug discovery, and beyond.

Meet the Organizers

Subham Sekhar Sahoo

Subham Sahoo

Holds a Ph.D. from Cornell Tech, where he specialized in Diffusion Language Models. He has made foundational contributions to the field, with his work deployed at scale by Google, NVIDIA, and ByteDance across language generation and drug discovery.

Justin Deschenaux

Justin Deschenaux

PhD student in Machine Learning at EPFL, advised by Prof. Caglar Gulcehre. Previously interned at Apple MLR. His research interests include diffusion language models, fast generative models, and generalization.

Zhihan Yang

Zhihan Yang

PhD student at Cornell CS. Previously completed his Bachelor's degrees in Mathematics and Statistics at Carleton College. He is a winner of the CRA Outstanding Undergraduate Researcher Award and his research focuses on principled, controllable, and efficient generative models.