arXiv Machine Learning

Propensity Straight-Through Gradients for Discrete Stochastic Systems

arXiv Machine Learning
Jun 10

Rare Event Analysis via Stochastic Optimal Control

arXiv:2604. 13213v2 Announce Type: replace-cross Abstract: Rare events such as conformational changes in biomolecules, phase transitions, and chemical reactions are central to the behavior of many physical systems, yet they are extremely difficult to study computationally because unbiased simulations seldom produce them.

By Yuanqi Du, Jiajun He, Dinghuai Zhang, Eric Vanden-Eijnden, Carles Domingo-Enrich
arXiv Machine Learning
Sep 18

Correlation-Free Transition Path Sampling through Shooting Point Generation Guided by Committor Learning

The paper introduces GenAIMMD, an iterative algorithm that learns the committor function and trains a conditioned Boltzmann Generator to generate uncorrelated transition paths without prior knowledge of the reaction coordinate. This method combines transition path sampling with committor learning, enabling fully parallelizable sampling. Benchmarks on a toy model and a polymer system show a substantial performance improvement over standard TPS.

By Maximilian Negedly, Sebastian Falkner, Alessandro Coretti, Christoph Dellago
arXiv Machine Learning
Sep 18

VGAS: Variance-Reduced Guidance and Adaptive Selection for Training-Free Reward Alignment in Discrete Diffusion

VGAS: Variance-Reduced Guidance and Adaptive Selection for Training-Free Reward Alignment in Discrete Diffusion proposes a new inference-time framework that improves steering of frozen masked discrete diffusion models. By reducing the variance of guidance estimates, applying reward tilting to clean-token logits, and adapting the selection temperature at each step, VGAS addresses three default choices in existing pipelines. Experiments on regulatory DNA, protein, and small-molecule benchmarks show that VGAS achieves the best training-free reward performance and matches or surpasses reward-fine-tuned generators.

By Kwanyoung Kim
arXiv Machine Learning
Oct 5

ENCORE: Exact Non-equilibrium COntrol with Replica Exchange for Diffusion Generation

ENCORE is a new exact parallel control method for inference‑time steering of pretrained generative models toward tilted target distributions. It uses replica exchange with each replica storing its trajectory, avoiding simulation of the intractable time reversal and ensuring target invariance. Experiments on synthetic, biomolecular, and image data show that ENCORE achieves competitive accuracy and diversity, remains robust to sampler perturbations, and works with distilled samplers where prior replica‑exchange corrections fail.

By Jiahao Yu, Saifuddin Syed, Jos\'e Miguel Hern\'andez-Lobato, Jiajun He
arXiv Machine Learning
Sep 29

CRNDiff: Count-Native Diffusion Framework via Chemical Reaction Networks

CRNDiff is a new count‑native diffusion framework that uses stochastic chemical reaction networks to model nonnegative integer data such as single‑cell RNA sequencing. It provides a closed‑form forward‑noising kernel, enabling efficient reverse sampling via forward‑filtering backward‑sampling and data‑driven selection of the terminal noising time. The method also introduces tilted Feynman–Kac steering to sample rare subpopulations without retraining, and demonstrates superior conditional fidelity and marker‑level preservation on human heart scRNA‑seq data.

By Yuxuan Qiu, Praful Gagrani, Tetsuya J Kobayashi