arXiv Machine Learning

On the Robustness of Langevin Dynamics to Score Function Error

arXiv:2603. 11319v2 Announce Type: replace Abstract: We consider the robustness of score-based generative modeling to errors in the estimate of the score function.

Hugging Face Trending Papers
Aug 6

The Tamed Subgradient Unadjusted Langevin Algorithm beyond Convexity

We study the problem of sampling from target distributions whose potentials are simultaneously non-smooth, subject to superlinear gradient growth, and non-convex. We introduce the Subgradient Tamed Unadjusted Langevin Algorithm (SG-TULA), a discretisation of the Langevin diffusion that operates directly on subgradients, without relying on computationally demanding smoothing procedures.

arXiv Machine Learning
Sep 14

Score-based Outlier Generation via Controlling the Radon-Nikodym Derivative

The paper introduces a measure‑theoretic definition of outliers based on the distribution of log‑likelihood values, ensuring that low‑likelihood events receive higher probability mass with a controllable magnitude. It shows how likelihood reweighting scales the diffusion score via the Radon‑Nikodym derivative, allowing the reverse‑time dynamics of a diffusion model to be modified without retraining. Using the Ornstein‑Uhlenbeck semigroup, the authors propose an exponentially interpolated controller that approximates the true control, enabling controlled generation of low‑likelihood samples that respect the data geometry.

By Amartya Mukherjee, Tristan Milne, Kry Yik-Chau Lui, Stephanie Hazlewood, Jun Liu
arXiv Machine Learning
Aug 27

Improved Analysis for Hessian-free High-resolution Monte Carlo Sampling

The paper introduces Hessian-free high-resolution (HFHR) dynamics, an extension of underdamped Langevin dynamics that incorporates reversible position diffusion for sampling in machine learning. It provides an explicit quantitative contraction rate under a position Poincaré inequality, weighted Hessian and Laplacian bounds, and a compact Sobolev embedding, even when the potential is non‑convex. For the HFHR Monte Carlo algorithm, a path‑space Girsanov argument yields a non‑asymptotic convergence bound and an explicit iteration complexity in total variation distance, improving on previous HFHR results and demonstrating benefits of a positive diffusion parameter through numerical experiments.

By Wujun Lv, Xiaoyu Wang, Yingli Wang, Lingjiong Zhu