[Submitted on 22 Jun 2026]

View PDF

Abstract:We identify the Poisson boundary of the one-point Schreier-chain random walk obtained by projecting the simple symmetric random walk on Thompson's group $F$ to the dyadic orbit point $1/2$. For the associated simple labelled-generator walk on the dyadic Schreier graph, the full Poisson boundary is the skeleton end boundary. The proof combines the known description of this Schreier graph as a binary-tree skeleton with recurrent one-dimensional ray attachments with an explicit trace computation. After tracing to the grey skeleton and deleting holding probabilities, the walk becomes a reversible nearest-neighbor walk on the rooted binary tree with two unequal classes of edge conductance. This reduces the boundary identification to standard Poisson--Martin theory for transient walks on trees and leaves a finite electrical-network calculation for the harmonic measure.
Following Kaimanovich's coding of skeleton ends by odd 2-adic integers [{\emph{Groups, Graphs and Random Walks}}, London Math. Soc. Lecture Note Ser.~436, pp.~300--342, 2017], the hitting measure is a biased Bernoulli product measure with explicitly computed bias. It is singular with respect to Haar measure, has full topological support, and is exact-dimensional; these properties and the exact constants are proved here.

Submission history

From: Christian Mönch [view email]
[v1] Mon, 22 Jun 2026 19:49:57 UTC (24 KB)

Current browse context:

math.PR

Bookmark

Bibliographic and Citation Tools

Code, Data and Media Associated with this Article

Demos

Recommenders and Search Tools

arXivLabs: experimental projects with community collaborators

arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.

Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.