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Nesetril and Ossona de Mendez introduced the notion of first order convergence, which unifies the notions of convergence for sparse and dense graphs. They asked whether if G_i is a sequence of graphs with M being their first order limit and…

Combinatorics · Mathematics 2019-02-20 Demetres Christofides , Daniel Kral

Ne\v{s}et\v{r}il and Ossona de Mendez recently proposed a new definition of graph convergence called structural convergence. The structural convergence framework is based on the probability of satisfaction of logical formulas from a fixed…

Combinatorics · Mathematics 2023-09-07 David Hartman , Tomáš Hons , Jaroslav Nešetřil

The notion of left convergent sequences of graphs introduced by Lov\' asz et al. (in relation with homomorphism densities for fixed patterns and Szemer\'edi's regularity lemma) got increasingly studied over the past $10$ years. Recently,…

Combinatorics · Mathematics 2015-09-18 Pierre Charbit , Lucas Hosseini , Patrice Ossona de Mendez

The theory of convergent graph sequences has been worked out in two extreme cases, dense graphs and bounded degree graphs. One can define convergence in terms of counting homomorphisms from fixed graphs into members of the sequence…

Combinatorics · Mathematics 2010-02-02 Christian Borgs , Jennifer Chayes , Jeff Kahn , László Lovász

In this paper we introduce a general framework for the study of limits of relational structures in general and graphs in particular, which is based on a combination of model theory and (functional) analysis. We show how the various…

Combinatorics · Mathematics 2021-04-23 Jaroslav Nesetril , Patrice Ossona De Mendez

Nesetril and Ossona de Mendez introduced the notion of first order convergence as an attempt to unify the notions of convergence for sparse and dense graphs. It is known that there exist first order convergent sequences of graphs with no…

A {\em string graph} is the intersection graph of a family of continuous arcs in the plane. The intersection graph of a family of plane convex sets is a string graph, but not all string graphs can be obtained in this way. We prove the…

Combinatorics · Mathematics 2018-03-20 János Pach , Bruce Reed , Yelena Yuditsky

We study the richness of the ensemble of graphical structures (i.e., unlabeled graphs) of the one-dimensional random geometric graph model defined by $n$ nodes randomly scattered in $[0,1]$ that connect if they are within the connection…

Information Theory · Computer Science 2022-06-24 Mihai-Alin Badiu , Justin P. Coon

It is known that families of graphs with a semialgebraic edge relation of bounded complexity satisfy much stronger regularity properties than arbitrary graphs, and that they can be decomposed into very homogeneous semialgebraic pieces up to…

Logic · Mathematics 2016-02-25 Artem Chernikov , Sergei Starchenko

We consider sequences of graphs and define various notions of convergence related to these sequences: ``left convergence'' defined in terms of the densities of homomorphisms from small graphs into the graphs of the sequence, and ``right…

Combinatorics · Mathematics 2007-05-23 C. Borgs , J. T. Chayes , L. Lovasz , V. T. Sos , K. Vesztergombi

We consider categories of relational structures that fully embed every category of universal algebras, and prove a partial characterisation of these in terms of an infinitary variant of the notion of nowhere density of Ne\v{s}et\v{r}il and…

Logic · Mathematics 2023-03-24 Ioannis Eleftheriadis

We introduce the concept of matching connectivity as a notion of connectivity in graph admitting perfect matchings which heavily relies on the structural properties of those matchings. We generalise a result of Robertson, Seymour and Thomas…

Combinatorics · Mathematics 2019-02-25 Archontia C. Giannopoulou , Stephan Kreutzer , Sebastian Wiederrecht

There are several notions of convergence for sequences of bounded degree graphs. One such notion is left convergence, which is based on counting neighborhood distributions. Another notion is right convergence, based on counting…

Combinatorics · Mathematics 2015-05-12 László Miklós Lovász

Based on methods of structural convergence we provide a unifying view of local-global convergence, fitting to model theory and analysis. The general approach outlined here provides a possibility to extend the theory of local-global…

Combinatorics · Mathematics 2018-10-18 Jaroslav Nesetril , Patrice Ossona de Mendez

Graphlets are subgraphs rooted at a fixed vertex. The number of occurrences of graphlets aligned to a particular vertex, called graphlet degree sequence (gds), gives a topological description of the surrounding of the analyzed vertex.…

Combinatorics · Mathematics 2026-01-01 David Hartman , Aneta Pokorná , Daniel Trlifaj , Lluís Vena

A sequence of graphs is FO-convergent if the probability of satisfaction of every first-order formula converges. A graph modeling is a graph, whose domain is a standard probability space, with the property that every definable set is Borel.…

Combinatorics · Mathematics 2026-04-15 J. Nesetril , P. Ossona de Mendez

The notion of first order convergence of graphs unifies the notions of convergence for sparse and dense graphs. Ne\v{s}et\v{r}il and Ossona de Mendez [J. Symbolic Logic 84 (2019), 452-472] proved that every first order convergent sequence…

Combinatorics · Mathematics 2025-12-22 Andrzej Grzesik , Daniel Kráľ , Samuel Mohr

The primary objective of this paper is to investigate the notions of geometric and sequential convexity within a graph-theoretic framework, with the aim of examining various structural properties and exploring the connection between these…

General Mathematics · Mathematics 2026-04-24 Angshuman R. Goswami

In a well-known paper[ARV], Arora, Rao and Vazirani obtained an O(sqrt(log n)) approximation to the Balanced Separator problem and Uniform Sparsest Cut. At the heart of their result is a geometric statement about sets of points that satisfy…

Discrete Mathematics · Computer Science 2011-02-09 Sanjeev Arora , James Lee , Sushant Sachdeva

We prove that every oriented tree on $n$ vertices with bounded maximum degree appears as a spanning subdigraph of every directed graph on $n$ vertices with minimum semidegree at least $n/2+o(n)$. This can be seen as a directed graph…

Combinatorics · Mathematics 2026-05-20 Richard Mycroft , Tássio Naia
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