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In Graph Minor III, Robertson and Seymour conjecture that the tree-width of a planar graph and that of its dual differ by at most one. We prove that given a hypergraph H on a surface of Euler genus k, the tree-width of H^* is at most the…

Discrete Mathematics · Computer Science 2008-12-17 Frédéric Mazoit

Over the last 30 years, researchers have investigated connections between dimension for posets and planarity for graphs. Here we extend this line of research to the structural graph theory parameter tree-width by proving that the dimension…

Combinatorics · Mathematics 2016-12-14 Gwenaël Joret , Piotr Micek , Kevin G. Milans , William T. Trotter , Bartosz Walczak , Ruidong Wang

We give a simple proof of the "tree-width duality theorem" of Seymour and Thomas that the tree-width of a finite graph is exactly one less than the largest order of its brambles.

Combinatorics · Mathematics 2013-09-10 Frédéric Mazoit

Given two $n$-vertex graphs $G_1$ and $G_2$ of bounded treewidth, is there an $n$-vertex graph $G$ of bounded treewidth having subgraphs isomorphic to $G_1$ and $G_2$? Our main result is a negative answer to this question, in a strong…

Combinatorics · Mathematics 2024-02-13 Bogdan Alecu , Vadim Lozin , Daniel A. Quiroz , Roman Rabinovich , Igor Razgon , Viktor Zamaraev

We define a special case of tree decompositions for planar graphs that respect a given embedding of the graph. We study the analogous width of the resulting decomposition we call the embedded-width of a plane graph. We show both upper…

Discrete Mathematics · Computer Science 2017-03-23 Glencora Borradaile , Jeff Erickson , Hung Le , Robbie Weber

We prove that the (divisorial) gonality of a finite connected graph is lower bounded by its treewidth. We show that equality holds for grid graphs and complete multipartite graphs. We prove that the treewidth lower bound also holds for…

Combinatorics · Mathematics 2022-01-04 Josse van Dobben de Bruyn , Dion Gijswijt

The treewidth of a graph is an important invariant in structural and algorithmic graph theory. This paper studies the treewidth of line graphs. We show that determining the treewidth of the line graph of a graph $G$ is equivalent to…

Combinatorics · Mathematics 2014-09-25 Daniel J. Harvey , David R. Wood

We establish relations between the bandwidth and the treewidth of bounded degree graphs G, and relate these parameters to the size of a separator of G as well as the size of an expanding subgraph of G. Our results imply that if one of these…

Combinatorics · Mathematics 2009-10-19 Julia Böttcher , Klaas P. Pruessmann , Anusch Taraz , Andreas Würfl

The connected tree-width of a graph is the minimum width of a tree-decomposition whose parts induce connected subgraphs. Long cycles are examples of graphs that have small tree-width but large connected tree-width. We show that a graph has…

Combinatorics · Mathematics 2015-10-15 Reinhard Diestel , Malte Müller

We apply a recent duality theorem for tangles in abstract separation systems to derive tangle-type duality theorems for width-parameters in graphs and matroids. We further derive a duality theorem for the existence of clusters in large data…

Combinatorics · Mathematics 2020-01-24 Reinhard Diestel , Sang-il Oum

It is known that any planar graph with diameter D has treewidth O(D), and this fact has been used as the basis for several planar graph algorithms. We investigate the extent to which similar relations hold in other graph families. We show…

Combinatorics · Mathematics 2010-01-21 David Eppstein

Tree-width is an invaluable tool for computational problems on graphs. But often one would like to compute on other kinds of objects (e.g. decorated graphs or even algebraic structures) where there is no known tree-width analogue. Here we…

Combinatorics · Mathematics 2022-06-22 Benjamin Merlin Bumpus , Zoltan A. Kocsis

Diestel and M\"uller showed that the connected tree-width of a graph $G$, i.e., the minimum width of any tree-decomposition with connected parts, can be bounded in terms of the tree-width of $G$ and the largest length of a geodesic cycle in…

Combinatorics · Mathematics 2017-02-15 Matthias Hamann , Daniel Weißauer

Consider a drawing of a graph $G$ in the plane such that crossing edges are coloured differently. The minimum number of colours, taken over all drawings of $G$, is the classical graph parameter "thickness". By restricting the edges to be…

Combinatorics · Mathematics 2015-06-17 Vida Dujmović , David R. Wood

We extend to infinite graphs the matroidal characterization of finite graph duality, that two graphs are dual iff they have complementary spanning trees in some common edge set. The naive infinite analogue of this fails. The key in an…

Combinatorics · Mathematics 2011-06-08 Reinhard Diestel , Julian Pott

The twin-width of a graph measures its distance to co-graphs and generalizes classical width concepts such as tree-width or rank-width. Since its introduction in 2020 (Bonnet et. al. 2020), a mass of new results has appeared relating twin…

Combinatorics · Mathematics 2024-11-21 Irene Heinrich , Simon Raßmann

We introduce the graph theoretical parameter of edge treewidth. This parameter occurs in a natural way as the tree-like analogue of cutwidth or, alternatively, as an edge-analogue of treewidth. We study the combinatorial properties of…

Discrete Mathematics · Computer Science 2021-12-15 Loïc Magne , Christophe Paul , Abhijat Sharma , Dimitrios M. Thilikos

The following theorem is proved: For all $k$-connected graphs $G$ and $H$ each with at least $n$ vertices, the treewidth of the cartesian product of $G$ and $H$ is at least $k(n -2k+2)-1$. For $n\gg k$ this lower bound is asymptotically…

Combinatorics · Mathematics 2013-10-02 David R. Wood

Twin-width is a newly introduced graph width parameter that aims at generalizing a wide range of "nicely structured" graph classes. In this work, we focus on obtaining good bounds on twin-width $\text{tww}(G)$ for graphs $G$ from a number…

Discrete Mathematics · Computer Science 2022-01-25 Hugo Jacob , Marcin Pilipczuk

In this paper, we characterise graphs that are quasi-isometric to graphs with bounded treewidth. Specifically, we prove that a graph is quasi-isometric to a graph with bounded treewidth if and only if it has a tree-decomposition where each…

Combinatorics · Mathematics 2025-08-21 Robert Hickingbotham
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