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We prove that every amenable one-ended Cayley graph has an invariant spanning tree of one end. More generally, for any 1-ended amenable unimodular random graph we construct a factor of iid percolation (jointly unimodular subgraph) that is…

Probability · Mathematics 2020-05-11 Adam Timar

We show that several new classes of groups are measure strongly treeable. In particular, finitely generated groups admitting planar Cayley graphs, elementarily free groups, and the group of isometries of the hyperbolic plane and all its…

Group Theory · Mathematics 2026-03-20 Clinton T. Conley , Damien Gaboriau , Andrew S. Marks , Robin D. Tucker-Drob

Given a group $G$, we define the power graph $\mathcal{P}(G)$ as follows: the vertices are the elements of $G$ and two vertices $x$ and $y$ are joined by an edge if $\langle x\rangle\subseteq \langle y\rangle$ or $\langle y\rangle\subseteq…

Group Theory · Mathematics 2017-05-16 A. R. Moghaddamfar , S. Rahbariyan , S. Navid Salehy , S. Nima Salehy

We prove the existence of an automorphism-invariant coupling for the wired and the free uniform spanning forests on Cayley graphs of finitely generated residually amenable groups.

Probability · Mathematics 2007-05-23 Lewis Bowen

A finite tree $T$ with $|V(T)| \geq 2$ is called {\it automorphism-free} if there is no non-trivial automorphism of $T$. Let $\mathcal{AFT}$ be the poset with the element set of all finite automorphism-free trees (up to graph isomorphism)…

Combinatorics · Mathematics 2013-03-08 Ilhee Kim , Ringi Kim , Paul Seymour

A graph $G$ is asymmetrizable if it has a set of vertices whose setwise stablizer only consists of the identity automorphism. The motion $m$ of a graph is the minimum number of vertices moved by any non-identity automorphism. It is known…

Combinatorics · Mathematics 2023-01-26 Wilfried Imrich , Rafał Kalinowski , Florian Lehner , Monika Pilśniak , Marcin Stawiski

This paper will show when a rooted path tree of a finite directed rooted graph has only finitely many orbits under the action of its undirected automorphism group (i.e. when it is cocompact). This will allow us to specify which trees are…

Combinatorics · Mathematics 2025-09-30 Roman Gorazd

We study the minimal spanning arborescence which is the directed analogue of the minimal spanning tree, with a particular focus on its infinite volume limit and its geometric properties. We prove that in a certain large class of transient…

Probability · Mathematics 2024-01-26 Gourab Ray , Arnab Sen

We establish three independent results on groups acting on trees. The first implies that a compactly generated locally compact group which acts continuously on a locally finite tree with nilpotent local action and no global fixed point is…

Group Theory · Mathematics 2018-12-19 Pierre-Emmanuel Caprace , Phillip Wesolek

We prove that the infinite components of the Free Uniform Spanning Forest of a Cayley graph are indistinguishable by any invariant property, given that the forest is different from its wired counterpart. Similar result is obtained for the…

Probability · Mathematics 2020-05-11 Adam Timar

A graph is one-ended if it contains a ray (a one way infinite path) and whenever we remove a finite number of vertices from the graph then what remains has only one component which contains rays. A vertex $v$ {\em dominates} a ray in the…

Combinatorics · Mathematics 2018-05-22 Johannes Carmesin , Florian Lehner , Rögnvaldur G. Möller

We prove the a.e. nonamenability of locally finite quasi-pmp Borel graphs whose every component admits at least three nonvanishing ends with respect to the underlying Radon--Nikodym cocycle. We witness their nonamenability by constructing…

Dynamical Systems · Mathematics 2025-12-30 Ruiyuan Chen , Grigory Terlov , Anush Tserunyan

We construct measures invariant with respect to equivalence relations which are graphed by horospheric products of trees. The construction is based on using conformal systems of boundary measures on treed equivalence relations. The…

Probability · Mathematics 2009-06-30 Vadim A. Kaimanovich , Florian Sobieczky

We show that every connected graph can be approximated by a normal tree, up to some arbitrarily small error phrased in terms of neighbourhoods around its ends. The existence of such approximate normal trees has consequences of both…

Combinatorics · Mathematics 2021-02-05 Jan Kurkofka , Ruben Melcher , Max Pitz

Gomory and Hu proved that if $ G $ is a finite graph with non-negative weights on its edges, then there exists a tree $ T $ (called now Gomory-Hu tree) on $ V(G) $ such that for all $ u\neq v\in V(G) $ there is an $ e\in E(T) $ such that…

Combinatorics · Mathematics 2017-04-25 Attila Joó

The Poisson boundary of a finite direct product of affine automorphism groups of homogeneous trees is considered. The Poisson boundary is shown to be a product of ends of trees with a hitting measure for spread-out, aperiodic measures of…

Group Theory · Mathematics 2017-08-24 John J. Harrison

Let T be a d-regular tree (d > 2) and A=Aut(T), its automorphism group. Let G be a group generated by n independent Haar-random elements of A. We show that almost surely, every nontrivial element of G has finitely many fixed points on T.

Group Theory · Mathematics 2008-10-10 Miklos Abert , Yair Glasner

In this paper, we investigate normal trees of directed graphs, which extend the fundamental concept of normal trees of undirected graphs. We prove that a directed graph $D$ has a normal spanning tree if and only if the topological space…

Combinatorics · Mathematics 2025-06-17 Florian Reich

This paper deals with graph automaton groups associated with trees and some generalizations. We start by showing some algebraic properties of tree automaton groups. Then we characterize the associated semigroup, proving that it is…

Group Theory · Mathematics 2023-04-10 Matteo Cavaleri , Daniele D'Angeli , Alfredo Donno , Emanuele Rodaro

The automorphism group of a regular locally finite tree is shown to admit irreducible Banach representations that are not admissible. The dense subspace of smooth vectors contains no algebraically irreducible component.

Group Theory · Mathematics 2026-03-18 Nicolas Monod
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