Imprecise Markov Semigroups and their Ergodicity

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Caprio, Michele, Chen, Mengqi
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915826090639360
author Caprio, Michele
Chen, Mengqi
author_facet Caprio, Michele
Chen, Mengqi
contents We introduce the concept of an imprecise Markov semigroup \(\mathbf Q\). It is a tool that allows us to represent ambiguity around both the transition probabilities and the invariant measure of a continuous-time Markov process via a collection of Markov semigroups, each associated with a (possibly different) Markov process. We use techniques from topology, geometry, and probability to analyze ergodic limits under model uncertainty encoded by \(\mathbf Q\). We establish long-term bounds that are uniform in the initial state and identify regimes in which the imprecision in these bounds collapses asymptotically. Our results are proved in progressively more general settings. We first assume that \(\mathbf Q\) is compact and that the state space is Euclidean or a Riemannian manifold, working with a fixed bounded observable. We then allow the state space to be standard Borel, while keeping \(\mathbf Q\) compact and the observable fixed. Finally, we drop compactness and work on Polish metric spaces of finite diameter, where we treat arbitrary bounded Lipschitz observables. The importance of our findings for the fields of artificial intelligence and computer vision is also discussed at a high level; In particular, in the study of how the probability of an output evolves over time as we perturb the input of a convolutional autoencoder.
format Preprint
id arxiv_https___arxiv_org_abs_2405_00081
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Imprecise Markov Semigroups and their Ergodicity
Caprio, Michele
Chen, Mengqi
Probability
Statistics Theory
Machine Learning
Primary: 60J60, Secondary: 58J65, 62A01
We introduce the concept of an imprecise Markov semigroup \(\mathbf Q\). It is a tool that allows us to represent ambiguity around both the transition probabilities and the invariant measure of a continuous-time Markov process via a collection of Markov semigroups, each associated with a (possibly different) Markov process. We use techniques from topology, geometry, and probability to analyze ergodic limits under model uncertainty encoded by \(\mathbf Q\). We establish long-term bounds that are uniform in the initial state and identify regimes in which the imprecision in these bounds collapses asymptotically. Our results are proved in progressively more general settings. We first assume that \(\mathbf Q\) is compact and that the state space is Euclidean or a Riemannian manifold, working with a fixed bounded observable. We then allow the state space to be standard Borel, while keeping \(\mathbf Q\) compact and the observable fixed. Finally, we drop compactness and work on Polish metric spaces of finite diameter, where we treat arbitrary bounded Lipschitz observables. The importance of our findings for the fields of artificial intelligence and computer vision is also discussed at a high level; In particular, in the study of how the probability of an output evolves over time as we perturb the input of a convolutional autoencoder.
title Imprecise Markov Semigroups and their Ergodicity
topic Probability
Statistics Theory
Machine Learning
Primary: 60J60, Secondary: 58J65, 62A01
url https://arxiv.org/abs/2405.00081