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Every graphon defines a random graph on any given number $n$ of vertices. It was known that the graphon is random-free if and only if the entropy of this random graph is subquadratic. We prove that for random-free graphons, this entropy can…

Combinatorics · Mathematics 2012-05-17 Hamed Hatami , Serguei Norine

We call a (not necessarily planar) embedding of a graph $G$ in the plane \emph{sequential} if its vertices lie in $\mathbb Z^2$ and the line segments between adjacent vertices contain no interior integer points. In this note, we prove (i) a…

Combinatorics · Mathematics 2018-12-10 Jackson Autry , Christopher O'Neill

We consider a class K of structures e.g. trees with omega +1 levels, metric spaces and mainly, classes of Abelian groups like the one mentioned in the title and the class of reduced separable (Abelian) p-groups. We say M in K is universal…

Logic · Mathematics 2022-10-25 Saharon Shelah

Graph embedding is a transformation of nodes of a graph into a set of vectors. A~good embedding should capture the graph topology, node-to-node relationship, and other relevant information about the graph, its subgraphs, and nodes. If these…

Social and Information Networks · Computer Science 2022-06-22 Arash Dehghan-Kooshkghazi , Bogumił Kamiński , Łukasz Kraiński , Paweł Prałat , François Théberge

We show that there are four infinite prime graphs such that every infinite prime graph with no infinite clique embeds one of these graphs. We derive a similar result for infinite prime posets with no infinite chain or no infinite antichain.

Combinatorics · Mathematics 2008-12-09 Maurice Pouzet , Imed Zaguia

The total embedding distributions of a graph is consisted of the orientable embeddings and non- orientable embeddings and have been know for few classes of graphs. The genus distribution of Ringel ladders is determined in [Discrete…

Combinatorics · Mathematics 2010-11-18 Yichao Chen , Lu Ou , Qian Zou

In this paper, we extend the ideas of graph pebbling to oriented graphs and find a classification for all graphs with fully traversable pebbling assignments that are isomorphic to their assignment graph. We then give some cases in which a…

Combinatorics · Mathematics 2022-03-02 Jared Glassband , Garrison Koch , Sophia Lebiere , Xufei Liu , Evan Sabini

We introduce the factorization graph of a finite group and study its connectedness and forbidden structures. We characterize all finite groups with connected factorization graphs and classify those with connected bipartite factorization…

Group Theory · Mathematics 2019-12-02 Mohammad Farrokhi Derakhshandeh Ghouchan , Ali Azimi

The independence density of a finite hypergraph is the probability that a subset of vertices, chosen uniformly at random contains no hyperedges. Independence densities can be generalized to countable hypergraphs using limits. We show that,…

Combinatorics · Mathematics 2016-04-20 Paul Balister , Béla Bollobás , Karen Gunderson

We show that the only random orderings of finite graphs that are invariant under isomorphism and induced subgraph are the uniform random orderings. We show how this implies the unique ergodicity of the automorphism group of the random…

Dynamical Systems · Mathematics 2018-09-10 Omer Angel , Alexander S. Kechris , Russell Lyons

The first part of the paper centers in the study of embeddability between partially commutative groups. In [KK], for a finite simplicial graph $\Gamma$, the authors introduce an infinite, locally infinite graph $\Gamma^e$, called the…

Group Theory · Mathematics 2015-06-11 Montserrat Casals-Ruiz

We prove that there is a second countable locally compact group that does not embed as a closed subgroup in any compactly generated locally compact group, and discuss various related embedding and non-embedding results.

Group Theory · Mathematics 2014-08-26 Pierre-Emmanuel Caprace , Yves Cornulier

We consider the number of crossings in a graph which is embedded randomly on a convex set of points. We give an estimate to the normal distribution in Kolmogorov distance which implies a convergence rate of order $n^{-1/2}$ for various…

Combinatorics · Mathematics 2022-08-26 Santiago Arenas-Velilla , Octavio Arizmendi

Cantor's famous proof of the non-denumerability of real numbers does apply to any infinite set. The set of exclusively all natural numbers does not exist. This shows that the concept of countability is not well defined. There remains no…

General Mathematics · Mathematics 2009-09-29 W. Mueckenheim

In this paper we are interested in an intrinsic property of graphs which is derived from their embeddings into the Euclidean 3-space $\mathbb{R}^3$. An embedding of a graph into $\mathbb{R}^3$ is said to be linear, if it sends every edge to…

Geometric Topology · Mathematics 2022-06-24 Youngsik Huh , Jung Hoon Lee

Solecki proved that the group of automorphisms of a countable structure cannot be an uncountable free abelian group. See more in Just, Shelah and Thomas math.LO/0003120 where as a by product we can say something on on uncountable…

Logic · Mathematics 2007-05-23 Saharon Shelah

We characterise finite axiomatisability and intractability of deciding membership for universal Horn classes generated by finite loop-free hypergraphs.

Combinatorics · Mathematics 2022-06-23 Lucy Ham , Marcel Jackson

A self-contained graph is an infinite graph which is isomorphic to one of its proper induced subgraphs. In this paper, these graphs are studied by presenting some examples and defining some of their sub-structures such as removable…

Combinatorics · Mathematics 2016-11-04 Mohammad Hadi Shekarriz , Madjid Mirzavaziri

We take an elementary and systematic approach to the problem of extending the Tutte polynomial to the setting of embedded graphs. Four notions of embedded graphs arise naturally when considering deletion and contraction operations on graphs…

Combinatorics · Mathematics 2023-01-02 Stephen Huggett , Iain Moffatt

By a regular embedding of a graph K in a surface we mean a 2-cell embedding of K in a compact connected surface such that the automorphism group acts regularly on flags. In this paper, we classify the nonorientable regular embeddings of the…

Combinatorics · Mathematics 2011-07-19 Gareth A. Jones , Young Soo Kwon
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