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The theory of graph limits represents large graphs by analytic objects called graphons. Graph limits determined by finitely many graph densities, which are represented by finitely forcible graphons, arise in various scenarios, particularly…

Combinatorics · Mathematics 2018-10-10 Jacob W. Cooper , Daniel Kral , Taisa L. Martins

A fundamental result of Mader from 1972 asserts that a graph of high average degree contains a highly connected subgraph with roughly the same average degree. We prove a lemma showing that one can strengthen Mader's result by replacing the…

Combinatorics · Mathematics 2013-05-21 Asaf Shapira , Benny Sudakov

We show that for sufficiently large $d$ and for $t\geq d+1$, there is a graph $G$ with average degree $(1-\varepsilon)\lambda t \sqrt{\ln d}$ such that almost every graph $H$ with $t$ vertices and average degree $d$ is not a minor of $G$,…

Combinatorics · Mathematics 2020-12-14 Sergey Norin , Bruce Reed , Andrew Thomason , David R. Wood

For a graph class $\mathcal{F}$, let $ex_{\mathcal{F}}(n)$ denote the maximum number of edges in a graph in $\mathcal{F}$ on $n$ vertices. We show that for every proper minor-closed graph class $\mathcal{F}$ the function…

Combinatorics · Mathematics 2020-09-29 Rohan Kapadia , Sergey Norin

In 2009, Krivelevich and Sudakov studied the existence of large complete minors in $(t,\alpha)$-expanding graphs whenever the expansion factor $t$ becomes super-constant. In this paper, we give an extension of the results of Krivelevich and…

Combinatorics · Mathematics 2021-09-10 Younjin Kim

In a series of three papers we develop an end space theory for digraphs. Here in the second paper we introduce the topological space $|D|$ formed by a digraph $D$ together with its ends and limit edges. We then characterise those digraphs…

Combinatorics · Mathematics 2020-09-08 Carl Bürger , Ruben Melcher

We study the joint degree counts in proportional attachment random graphs and find a simple representation for the limit distribution in infinite sequence space. We show weak convergence with respect to the p-norm topology for appropriate p…

Probability · Mathematics 2016-12-09 Erol A. Peköz , Adrian Röllin , Nathan Ross

We prove that a class of graphs with an excluded minor and with the maximum degree sublinear in the number of edges is maximally modular, that is, modularity tends to 1 as the number of edges tends to infinity.

Combinatorics · Mathematics 2021-02-16 Michał Lasoń , Małgorzata Sulkowska

A graph $U$ is universal for a graph class $\mathcal{C}\ni U$, if every $G\in \mathcal{C}$ is a minor of $U$. We prove the existence or absence of universal graphs in several natural graph classes, including graphs component-wise embeddable…

Combinatorics · Mathematics 2022-12-13 Agelos Georgakopoulos

We study the metric dimension (strong and weak) of infinite graphs. In particular, our main interest is characterizing infinite graphs with finite dimension. Our main results: (1) graphs with more than one end have infinite strong…

Combinatorics · Mathematics 2026-04-17 Csaba Biró , Caroline E. Boone , Beth Novick , Hazel Torek

It was proved by Huynh, Mohar, \v{S}\'amal, Thomassen and Wood in 2021 that any countable graph containing every countable planar graph as a subgraph has an infinite clique minor. We prove a finite, quantitative version of this result: for…

The concepts of domination and topological index hold great significance within the realm of graph theory. Therefore, it is pertinent to merge these concepts to derive the domination index of a graph. A novel concept of the domination index…

Combinatorics · Mathematics 2023-07-21 Kavya. R. Nair , M. S. Sunitha

It has been conjectured that if a finite graph has a vertex coloring such that the union of any two color classes induces a connected graph, then for every set $T$ of vertices containing exactly one member from each color class there exists…

Combinatorics · Mathematics 2019-11-19 Matthias Kriesell , Samuel Mohr

We study the Localization game on locally finite graphs trees, where each of the countably many vertices have finite degree. In contrast to the finite case, we construct a locally finite tree with localization number $n$ for any choice of…

Combinatorics · Mathematics 2024-04-04 Anthony Bonato , Florian Lehner , Trent G. Marbach , JD Nir

A random rooted graph is said to be sofic if it is the Benjamini-Schramm limit of a sequence of finite graphs. Given any finite graph $H$, we prove that every one-ended, unimodular random rooted graph that does not have H as a minor must be…

Combinatorics · Mathematics 2025-10-14 Oriol Solé-Pi

Two of the natural topologies for infinite graphs with edge-ends are Etop and Itop. In this paper, we study and characterize them. We show that Itop can be constructed by inverse limits of inverse systems of graphs with finitely many…

General Topology · Mathematics 2016-12-20 Babak Miraftab

We apply model theoretic methods to the problem of existence of countable universal graphs with finitely many forbidden connected subgraphs. We show that to a large extent the question reduces to one of local finiteness of an…

Logic · Mathematics 2016-09-07 Gregory Cherlin , Saharon Shelah , Niandong Shi

We give a sufficient condition on totally disconnected topological graphs such that their associated topological graph algebras are purely infinite.

Operator Algebras · Mathematics 2017-03-31 Hui Li

Making use of a majorization technique for a suitable class of graphs, we derive upper and lower bounds for some topological indices depending on the degree sequence over all vertices, namely the first general Zagreb index and the first…

Combinatorics · Mathematics 2015-03-27 Monica Bianchi , Alessandra Cornaro , José Luis Palacios , Anna Torriero

A set of vertices $S$ \emph{resolves} a graph $G$ if every vertex is uniquely determined by its vector of distances to the vertices in $S$. The \emph{metric dimension} of a graph $G$ is the minimum cardinality of a resolving set. In this…

Combinatorics · Mathematics 2009-05-01 J. Cáceres , C. Hernando , M. Mora , M. L. Puertas , I. M. Pelayo