Rebalancing Markov jump processes for non-reversible continuous-time sampling
Erik Jansson, Moritz Schauer, Ruben Seyer, Akash Sharma
TL;DR
The paper addresses slow mixing in reversible sampling by introducing a rebalancing device that converts skew-detailed-balanced Markov jump processes into non-reversible continuous-time samplers targeting $\pi$, with minimal rejection and no repeated proposals. It builds lifted samplers (FFF and BJS) via a reference measure, a $\pi$-isometric involution $\mathfrak{s}$, and a balancing function $g$, enabling unbounded balancing and simple kernel composition. Theoretical contributions include invariance, non-explosion, and geometric ergodicity results under mild tail and smoothness conditions, along with a detailed drift–minorization analysis for the FFF class. Empirical results on Bayesian logistic regression, Rosenbrock banana, and Bayesian PKPD demonstrate robustness to tuning and improved efficiency relative to Metropolis-based and standard HMC approaches, highlighting practical scalability for Bayesian inference in complex geometries.
Abstract
Markov chain Monte Carlo methods are central in computational statistics, and typically rely on detailed balance to ensure invariance with respect to a target distribution. Although straightforward to construct by Metropolization, this can induce diffusion-like exploration of the sample space, requiring careful tuning of parameters such as step size. We introduce a general mechanism for constructing non-reversible continuous-time samplers, without requiring detailed balance. Our approach transforms jump processes satisfying a skew-detailed balance condition for a reference measure into processes sampling a target measure absolutely continuous with respect to it. Unbounded balancing functions allow such samplers to dynamically select favourable transitions. We establish invariance under weak criteria and demonstrate how to verify geometric ergodicity. Numerical experiments demonstrate that the resulting samplers are more robust to parameter tuning.
