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Lookup NU author(s): Dr Giorgos VasdekisORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
The Zig-Zag process is a piecewise deterministic Markov process, efficiently used for simulation in an MCMC setting. As we show in this article, it fails to be exponentially ergodic on heavy tailed target distributions. We introduce an extension of the Zig-Zag process by allowing the process to move with a nonconstant speed function s, depending on the current state of the process. We call this process Speed Up Zig-Zag (SUZZ). We provide conditions that guarantee stability properties for the SUZZ process, including nonexplosivity, exponential ergodicity in heavy tailed targets and central limit theorem. Interestingly, we find that using speed functions that induce explosive deterministic dynamics may lead to stable algorithms that can even mix faster. We further discuss the choice of an efficient speed function by providing an efficiency criterion for the one-dimensional process and we support our findings with simulation results.
Author(s): Vasdekis G, Roberts GO
Publication type: Article
Publication status: Published
Journal: Annals of Applied Probability
Year: 2023
Volume: 33
Issue: 6A
Pages: 4693-4746
Print publication date: 04/12/2023
Online publication date: 04/12/2023
Acceptance date: 05/01/2023
Date deposited: 20/06/2024
ISSN (print): 1050-5164
ISSN (electronic): 2168-8737
Publisher: Institute of Mathematical Statistics
URL: https://doi.org/10.1214/23-AAP1930
DOI: 10.1214/23-AAP1930
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