English
Related papers

Related papers: A counterexample regarding labelled well-quasi-ord…

200 papers

We are interested in characterizing which classes of finite graphs are well-quasi-ordered by the induced subgraph relation. To that end, we devise an algorithm to decide whether a class of finite graphs well-quasi-ordered by the induced…

Logic in Computer Science · Computer Science 2024-07-02 Aliaume Lopez

Daligault, Rao and Thomass\'e asked whether a hereditary class of graphs well-quasi-ordered by the induced subgraph relation has bounded clique-width. Lozin, Razgon and Zamaraev recently showed that this is not true for classes defined by…

Combinatorics · Mathematics 2016-11-14 Konrad K. Dabrowski , Vadim V. Lozin , Daniël Paulusma

We study classes of graphs with bounded clique-width that are well-quasi-ordered by the induced subgraph relation, in the presence of labels on the vertices. We prove that, given a finite presentation of a class of graphs, one can decide…

Combinatorics · Mathematics 2026-05-29 Maël Dumas , Aliaume Lopez

We present a hereditary class of graphs of unbounded clique-width which is well-quasi-ordered by the induced subgraph relation. This result provides a negative answer to the question asked by Daligault, Rao and Thomass\'e in…

Discrete Mathematics · Computer Science 2015-03-03 Vadim Lozin , Igor Razgon , Viktor Zamaraev

A well-quasi-order is an order which contains no infinite decreasing sequence and no infinite collection of incomparable elements. In this paper, we consider graph classes defined by excluding one graph as contraction. More precisely, we…

Combinatorics · Mathematics 2016-12-20 Marcin Kamiński , Jean-Florent Raymond , Théophile Trunck

Balogh, Bollobas and Weinreich showed that a parameter that has since been termed the distinguishing number can be used to identify a jump in the possible speeds of hereditary classes of graphs at the sequence of Bell numbers. We prove that…

Combinatorics · Mathematics 2019-05-13 Aistis Atminas , Robert Brignall

While the theory of labelled well-quasi-order has received significant attention in the graph setting, it has not yet been considered in the context of permutation patterns. We initiate this study here, and show how labelled well quasi…

Combinatorics · Mathematics 2022-10-06 Robert Brignall , Vincent Vatter

We study bipartite graphs partially ordered by the induced subgraph relation. Our goal is to distinguish classes of bipartite graphs which are or are not well-quasi-ordered (wqo) by this relation. Answering an open question from…

Combinatorics · Mathematics 2010-05-11 Nicholas Korpelainen , Vadim V. Lozin

S. B. Rao conjectured that graphic sequences are well-quasi-ordered under an inclusion based on induced subgraphs. This conjecture has now been proved by Chudnovsky and Seymour. We give an independent short proof of the labelled version of…

Combinatorics · Mathematics 2013-06-18 Vaidy Sivaraman

This paper is a contribution to the study of hereditary classes of relational structures, these classes being quasi-ordered by embeddability. It deals with the specific case of ordered sets of width two and the corresponding bichains and…

Combinatorics · Mathematics 2022-08-30 Maurice Pouzet , Imed Zaguia

Recently, Daligault, Rao and Thomass\'e asked in [3] if every hereditary class which is well-quasi-ordered by the induced subgraph relation is of bounded clique-width. There are two reasons why this questions is interesting. First, it…

Combinatorics · Mathematics 2015-08-26 Aistis Atminas , Vadim V. Lozin , Igor Razgon

Daligault, Rao and Thomass\'e asked whether every hereditary graph class that is well-quasi-ordered by the induced subgraph relation has bounded clique-width. Lozin, Razgon and Zamaraev (JCTB 2017+) gave a negative answer to this question,…

Combinatorics · Mathematics 2017-11-27 Konrad K. Dabrowski , Vadim V. Lozin , Daniël Paulusma

One of the main questions that arise when studying random and quasi-random structures is which properties P are such that any object that satisfies P "behaves" like a truly random one. In the context of graphs, Chung, Graham, and Wilson…

Combinatorics · Mathematics 2009-03-03 Asaf Shapira , Raphael Yuster

Nash-Williams' Strong Immersion Conjecture states that graphs are well-quasi-ordered by the strong immersion relation. That is, given infinitely many graphs, one graph contains another graph as a strong immersion. In this paper we study the…

Combinatorics · Mathematics 2024-12-16 Chun-Hung Liu , Irene Muzi

We consider well-quasi-order for classes of permutation graphs which omit both a path and a clique. Our principle result is that the class of permutation graphs omitting $P_5$ and a clique of any size is well-quasi-ordered. This is proved…

Combinatorics · Mathematics 2015-04-28 Aistis Atminas , Robert Brignall , Nicholas Korpelainen , Vadim Lozin , Vincent Vatter

In this paper we consider the question of well quasi-order for classes defined by a single obstruction within the classes of all graphs, digraphs and tournaments, under the homomorphic image ordering (in both its standard and strong forms).…

Combinatorics · Mathematics 2017-03-17 N. Ruskuc , Sophie Huczynska

Robertson and Seymour's celebrated Graph Minor Theorem states that graphs are well-quasi-ordered by the minor relation. Unlike the minor relation, the topological minor relation does not well-quasi-order graphs in general. Among all known…

Combinatorics · Mathematics 2024-12-30 Chun-Hung Liu , Robin Thomas

In descending generality I survey: five partial orderings of graphs, the induced-subgraph ordering, and examples like perfect, threshold, and mock threshold graphs. The emphasis is on how the induced subgraph ordering differs from other…

Combinatorics · Mathematics 2021-06-21 Thomas Zaslavsky

The central theorem of topological graph theory states that the graph minor relation is a well-quasi-order on graphs. It has far-reaching consequences, in particular in the study of graph structures and the design of (parameterized)…

Computational Geometry · Computer Science 2025-12-04 Corentin Lunel , Clément Maria

A graph property (i.e., a set of graphs) is induced-hereditary or additive if it is closed under taking induced-subgraphs or disjoint unions. If $\cP$ and $\cQ$ are properties, the product $\cP \circ \cQ$ consists of all graphs $G$ for…

Combinatorics · Mathematics 2007-05-23 A. Farrugia , R. Bruce Richter , G. Semanisin
‹ Prev 1 2 3 10 Next ›