The Poisson boundary of Thompson's group $T$ is not the circle
Dynamical Systems
2025-04-03 v1 Group Theory
Probability
Abstract
Let be a nondegenerate probability measure with finite entropy on a countable group of orientation-preserving homeomorphisms of the circle acting proximally, minimally and topologically nonfreely on . We prove that the circle endowed with its unique -stationary probability measure is not the Poisson boundary of . When is Thompson's group and is finitely supported, this answers a question posed by B. Deroin [Ergodic Theory Dynam. Systems, 2013] and A. Navas [Proceedings of the International Congress of Mathematicians, 2018].
Keywords
Cite
@article{arxiv.2504.01283,
title = {The Poisson boundary of Thompson's group $T$ is not the circle},
author = {Martín Gilabert Vio and Cosmas Kravaris and Eduardo Silva},
journal= {arXiv preprint arXiv:2504.01283},
year = {2025}
}