59:12
published on October 24, 2025
Problèmes ouverts et progrès récents en géométrie spectrale hyperbolique
By Frédéric Naud
By Josh Frisch
Appears in collection : 2022 - T2 - WS2 - Self-similarity of groups, trees and fractals
The Poisson boundary of a group is a probabilistic object which serves a dual role. It represents the space of asymptotic trajectories a random walk might take and it represents the possible space of bounded harmonic functions on a group.
In this talk I will discuss the Poisson boundary for linear groups. In particular I will focus on the question of when the boundary is trivial in which case all bounded harmonic functions on the group are constant. This is joint work with Anna Erschler.