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Related papers: Invariant random matchings in Cayley graphs

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We prove that every (possibly infinite) graph of degree at most $d$ has a 4-dependent random proper $4^{d(d+1)/2}$-coloring, and one can construct it as a finitary factor of iid. For unimodular transitive (or unimodular random) graphs we…

Probability · Mathematics 2024-02-28 Ádám Timár

Extending the notion of (random) $k$-out graphs, we consider when the $k$-out hypergraph is likely to have a perfect fractional matching. In particular, we show that for each $r$ there is a $k=k(r)$ such that the $k$-out $r$-uniform…

Combinatorics · Mathematics 2017-03-13 Pat Devlin , Jeff Kahn

In this paper, we prove that the 2-factor polynomial, an invariant of a planar trivalent graph with a perfect matching, counts the number of 2- factors that contain the the perfect matching as a subgraph. Consequently, we show that the…

Combinatorics · Mathematics 2020-06-02 Scott Baldridge , Adam M. Lowrance , Ben McCarty

We show that any finitely dependent invariant process on a transitive amenable graph is a finitary factor of an i.i.d. process. With an additional assumption on the geometry of the graph, namely that no two balls with different centers are…

Probability · Mathematics 2020-01-22 Yinon Spinka

Due to their elegant and simple nature, unitary Cayley graphs have been an active research topic in the literature. These graphs are naturally connected to several branches of mathematics, including number theory, finite algebra,…

Combinatorics · Mathematics 2024-09-04 Ján Mináč , Tung T. Nguyen , Nguyen Duy Tân

We characterize the finitely generated groups that admit a Cayley graph whose only automorphisms are the translations, confirming a conjecture by Watkins from 1976. The proof relies on random walk techniques. As a consequence, every…

Group Theory · Mathematics 2024-03-21 Paul-Henry Leemann , Mikael de la Salle

Let S be a finite generating set of a torsion-free, nilpotent group G. We show that every automorphism of the Cayley graph Cay(G;S) is affine. (That is, every automorphism of the graph is obtained by composing a group automorphism with…

Combinatorics · Mathematics 2016-03-14 Dave Witte Morris , Joy Morris , Gabriel Verret

In this note we study inhomogeneous random bipartite graphs in random environment. These graphs can be thought of as an extension of the classical Erd\"os-R\'enyi random graphs in a random environment. We show that the expected number of…

Combinatorics · Mathematics 2016-11-29 Jairo Bochi , Godofredo Iommi , Mario Ponce

We continue the study of the properties of graphs in which the ball of radius $r$ around each vertex induces a graph isomorphic to the ball of radius $r$ in some fixed vertex-transitive graph $F$, for various choices of $F$ and $r$. This is…

Combinatorics · Mathematics 2020-11-25 Itai Benjamini , David Ellis

We say that a $d$-regular graph is a $\gamma$-expander if for every not too large set of vertices $S$, there are at least $\gamma d |S|$ edges leaving $S$, and we say that a graph $G$ is $\gamma$-far from bipartite if at least $\gamma e(G)$…

Combinatorics · Mathematics 2026-05-15 Domagoj Bradač , Oliver Janzer

In this paper, we generalize the notions of perfect matchings, perfect 2-matchings to perfect k-matchings and give a necessary and sufficient condition for existence of perfect k-matchings. For bipartite graphs, we show that this k-matching…

Combinatorics · Mathematics 2010-08-26 Hongliang Lu

We establish a sharp edge-connectivity estimate for graphs with non-negative Bakry-\'Emery curvature. This leads to a geometric criterion for the existence of a perfect matching. Precisely, we show that any regular graph with non-negative…

Combinatorics · Mathematics 2025-07-25 Kaizhe Chen , Jack H. Koolen , Shiping Liu

Consider the graph obtained by superposition of an independent pair of uniform infinite non-crossing perfect matchings of the set of integers. We prove that this graph contains at most one infinite path. Several motivations are discussed.

Probability · Mathematics 2017-01-24 Nicolas Curien , Gady Kozma , Vladas Sidoravicius , Laurent Tournier

We prove an upper bound on the number of pairwise strongly cospectral vertices in a normal Cayley graph, in terms of the multiplicities of its eigenvalues. We use this to determine an explicit bound in Cayley graphs of $\mathbb{Z}_2^d$ and…

Combinatorics · Mathematics 2023-05-19 Arnbjörg Soffía Árnadóttir , Chris Godsil

In this report, we describe a novel graph invariant for computational graphs (colored directed acylic graphs) and how we used it to generate all distinct computational graphs up to isomorphism for small graphs. The algorithm iteratively…

Discrete Mathematics · Computer Science 2019-02-19 Chris Ying

We define a range of new coarse geometric invariants based on various graph-theoretic measures of complexity for finite graphs, including: treewidth, pathwidth, cutwidth and bandwidth. We prove that, for bounded degree graphs, these…

Metric Geometry · Mathematics 2025-08-07 Wanying Huang , David Hume , Samuel J. Kelly , Ryan Lam

We prove that in all regular robust expanders $G$ every edge is asymptotically equally likely contained in a uniformly chosen perfect matching $M$. We also show that given any fixed matching or spanning regular graph $N$ in $G$, the random…

Combinatorics · Mathematics 2023-11-28 Bertille Granet , Felix Joos

Nash-Williams proved that every graph has a well-balanced orientation. A key ingredient in his proof is admissible odd-vertex pairings. We show that for two slightly different definitions of admissible odd-vertex pairings, deciding whether…

Combinatorics · Mathematics 2022-06-15 Florian Hörsch

We prove that a connected, locally finite, quasi-transitive graph which is quasi-isometric to a planar graph is necessarily accessible. This leads to a complete classification of the finitely generated groups which are quasi-isometric to…

Group Theory · Mathematics 2026-05-14 Joseph Paul MacManus

We prove that every 2k-edge-connected graph with countably many edge-ends admits a k-arc-connected orientation, extending the previous result by Assem, Koloschin and Pitz that also assumed the hypothesis of the graph being locally finite.…

Combinatorics · Mathematics 2025-10-09 Leandro Aurichi , Paulo Magalhães Júnior , Guilherme Eduardo Pinto