The structure of quasi-transitive graphs avoiding a minor with applications to the domino problem

L Esperet, U Giocanti, C Legrand-Duchesne - Journal of Combinatorial …, 2024 - Elsevier
An infinite graph is quasi-transitive if its vertex set has finitely many orbits under the action of
its automorphism group. In this paper we obtain a structure theorem for locally finite quasi …

Canonical graph decompositions via coverings

R Diestel, RW Jacobs, P Knappe, J Kurkofka - arXiv preprint arXiv …, 2022 - arxiv.org
We present a canonical way to decompose finite graphs into highly connected local parts.
The decomposition depends only on an integer parameter whose choice sets the intended …

Asymptotic half-grid and full-grid minors

S Albrechtsen, M Hamann - arXiv preprint arXiv:2412.15675, 2024 - arxiv.org
We prove that every locally finite, quasi-transitive graph with a thick end whose cycle space
is generated by cycles of bounded length contains the full-grid as an asymptotic minor and …

Quasi-transitive K∞-minor free graphs

M Hamann - European Journal of Combinatorics, 2025 - Elsevier
We prove that every locally finite quasi-transitive graph that does not contain K∞ as a minor
is quasi-isometric to some planar quasi-transitive locally finite graph. This solves a problem …

Towards a Stallings-type theorem for finite groups

J Carmesin, G Kontogeorgiou, J Kurkofka… - arXiv preprint arXiv …, 2024 - arxiv.org
A recent development in graph theory is to study local separators, vertex sets that need not
separate graphs globally but just locally. We use this idea to conjecture an extension of …

Hyperfiniteness of boundary actions of relatively hyperbolic groups

C Karpinski - Groups, Geometry, and Dynamics, 2024 - ems.press
We show that if G is a finitely generated group hyperbolic relative to a finite collection of
subgroups P, then the natural action of G on the geodesic boundary of the associated …

Self-avoiding walks and multiple context-free languages

F Lehner, C Lindorfer - arXiv preprint arXiv:2010.06974, 2020 - arxiv.org
Let $ G $ be a quasi-transitive, locally finite, connected graph rooted at a vertex $ o $, and let
$ c_n (o) $ be the number of self-avoiding walks of length $ n $ on $ G $ starting at $ o $. We …

A note on the structure of locally finite planar quasi-transitive graphs

U Giocanti - arXiv preprint arXiv:2412.20300, 2024 - arxiv.org
In an early work from 1896, Maschke established the complete list of all finite planar Cayley
graphs. This result initiated a long line of research over the next century, aiming at …

Periodic colorings and orientations in infinite graphs

T Abrishami, L Esperet, U Giocanti, M Hamann… - arXiv preprint arXiv …, 2024 - arxiv.org
We study the existence of periodic colorings and orientations in locally finite graphs. A
coloring or orientation of a graph $ G $ is periodic if the resulting colored or oriented graph is …

Subsets of groups with context-free preimages

A Levine - arXiv preprint arXiv:2312.04191, 2023 - arxiv.org
We study subsets $ E $ of finitely generated groups where the set of all words over a given
finite generating set that lie in $ E $ forms a context-free language. We call these sets …