English
Related papers

Related papers: A Flat Wall Theorem for Matching Minors in Biparti…

200 papers

We prove a duality theorem applicable to a a wide range of specialisations, as well as to some generalisations, of tangles in graphs. It generalises the classical tangle duality theorem of Robertson and Seymour, which says that every graph…

Combinatorics · Mathematics 2017-07-07 Reinhard Diestel , Philipp Eberenz , Joshua Erde

We prove that a minor-closed class of graphs has bounded layered pathwidth if and only if some apex-forest is not in the class. This generalises a theorem of Robertson and Seymour, which says that a minor-closed class of graphs has bounded…

Combinatorics · Mathematics 2020-08-03 Vida Dujmović , David Eppstein , Gwenaël Joret , Pat Morin , David R. Wood

Treewidth is a graph parameter that plays a fundamental role in several structural and algorithmic results. We study the problem of decomposing a given graph $G$ into node-disjoint subgraphs, where each subgraph has sufficiently large…

Data Structures and Algorithms · Computer Science 2013-04-08 Chandra Chekuri , Julia Chuzhoy

We introduce a supporting combinatorial framework for the Flat Wall Theorem. In particular, we suggest two variants of the theorem and we introduce a new, more versatile, concept of wall homogeneity as well as the notion of regularity in…

Discrete Mathematics · Computer Science 2022-10-06 Ignasi Sau , Giannos Stamoulis , Dimitrios M. Thilikos

Robertson and Seymour proved that the relation of graph immersion is well-quasi-ordered for finite graphs. Their proof uses the results of graph minors theory. Surprisingly, there is a very short proof of the corresponding rough structure…

Combinatorics · Mathematics 2012-07-10 Matt DeVos , Jessica McDonald , Bojan Mohar , Diego Scheide

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

The main result of the paper is motivated by the following two, apparently unrelated graph optimization problems: (A) as an extension of Edmonds' disjoint branchings theorem, characterize digraphs comprising $k$ disjoint branchings $B_i$…

Combinatorics · Mathematics 2017-09-05 Kristóf Bérczi , András Frank

The graph minor structure theorem by Robertson and Seymour shows that every graph that excludes a fixed minor can be constructed by a combination of four ingredients: graphs embedded in a surface of bounded genus, a bounded number of…

Combinatorics · Mathematics 2015-03-19 Gwenaël Joret , David R. Wood

The bidimensionality of a set of vertices $X$ in a graph $G$ is the maximum $k$ for which $G$ contains as a $X$-rooted minor the $(k \times k)$-grid. This notion allows for the following version of the Graph Minors Structure Theorem (GMST)…

Combinatorics · Mathematics 2026-05-27 Dimitrios M. Thilikos , Sebastian Wiederrecht

We define the graph minor category and prove that the category of contravariant representations of the graph minor category over a Noetherian ring is locally Noetherian. This can be regarded as a categorification of the Robertson--Seymour…

Combinatorics · Mathematics 2022-04-19 Dane Miyata , Nicholas Proudfoot , Eric Ramos

Let $\mathcal{D}_k$ be the class of graphs for which every minor has minimum degree at most $k$. Then $\mathcal{D}_k$ is closed under taking minors. By the Robertson-Seymour graph minor theorem, $\mathcal{D}_k$ is characterised by a finite…

Combinatorics · Mathematics 2011-06-07 Gašper Fijavž , David R. Wood

The grid theorem, originally proved by Robertson and Seymour in Graph Minors V in 1986, is one of the most central results in the study of graph minors. It has found numerous applications in algorithmic graph structure theory, for instance…

Discrete Mathematics · Computer Science 2022-05-09 Ken-ichi Kawarabayashi , Stephan Kreutzer

In the first paper of the Graph Minors series [JCTB '83], Robertson and Seymour proved the Forest Minor theorem: the $H$-minor-free graphs have bounded pathwidth if and only if $H$ is a forest. In recent years, considerable effort has been…

Combinatorics · Mathematics 2025-12-02 Édouard Bonnet , Benjamin Duhamel , Robert Hickingbotham

A connected graph G is called matching covered if every edge of G is contained in a perfect matching. Perfect matching width is a width parameter for matching covered graphs based on a branch decomposition. It was introduced by Norine and…

Combinatorics · Mathematics 2019-02-15 Meike Hatzel , Roman Rabinovich , Sebastian Wiederrecht

Leighton's graph covering theorem states that a pair of finite graphs with isomorphic universal covers have a common finite cover. We provide a new proof of Leighton's theorem that allows generalizations; we prove the corresponding result…

Group Theory · Mathematics 2018-07-31 Daniel J. Woodhouse

We investigate a structural generalisation of treewidth we call $\mathcal{A}$-blind-treewidth where $\mathcal{A}$ denotes an annotated graph class. This width parameter is defined by evaluating only the size of those bags $B$ of…

Combinatorics · Mathematics 2024-10-03 J. Pascal Gollin , Sebastian Wiederrecht

The Graph Minor Theorem of Robertson and Seymour implies a finite set of obstructions for any minor closed graph property. We show that there are only three obstructions to knotless embedding of size 23, which is far fewer than the 92 of…

Geometric Topology · Mathematics 2024-05-02 Hyoungjun Kim , Thomas W. Mattman

We introduce a homotopy theory of digraphs (directed graphs) and prove its basic properties, including the relations to the homology theory of digraphs constructed by the authors in previous papers. In particular, we prove the homotopy…

Algebraic Topology · Mathematics 2014-07-02 Alexander Grigor'yan , Yong Lin , Yuri Muranov , Shing-Tung Yau

An infinite graph is quasi-transitive if its vertex set has finitely many orbits under the action of its automorphism group. In this paper we obtain a structure theorem for locally finite quasi-transitive graphs avoiding a minor, which is…

Combinatorics · Mathematics 2024-09-13 Louis Esperet , Ugo Giocanti , Clément Legrand-Duchesne

The present paper is the first one in the sequence of papers about a simple class of {\em framed $4$-graphs}; the goal of the present paper is to collect some well-known results on planarity and to reformulate them in the language of {\em…

Combinatorics · Mathematics 2014-02-10 Vassily Olegovich Manturov