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Treewidth is a well-known graph invariant with multiple interesting applications in combinatorics. On the practical side, many NP-complete problems are polynomial-time (sometimes even linear-time) solvable on graphs of bounded treewidth. On…

Category Theory · Mathematics 2021-05-13 Zoltan A. Kocsis , Benjamin Merlin Bumpus

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 introduce structured decompositions, category-theoretic structures which simultaneously generalize notions from graph theory (including treewidth, layered treewidth, co-treewidth, graph decomposition width, tree independence number,…

Category Theory · Mathematics 2025-05-21 Benjamin Merlin Bumpus , Zoltan A. Kocsis , Jade Edenstar Master , Emilio Minichiello

We introduce monoidal width as a measure of the difficulty of decomposing morphisms in monoidal categories. For graphs, we show that monoidal width and two variations capture existing notions, namely branch width, tree width and path width.…

Category Theory · Mathematics 2022-05-18 Elena Di Lavore , Paweł Sobociński

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

Tree-cut width is a graph parameter introduced by Wollan that is an analogue of treewidth for the immersion order on graphs in the following sense: the tree-cut width of a graph is functionally equivalent to the largest size of a wall that…

Combinatorics · Mathematics 2022-08-12 Łukasz Bożyk , Oscar Defrain , Karolina Okrasa , Michał Pilipczuk

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

Decompositional parameters such as treewidth are commonly used to obtain fixed-parameter algorithms for NP-hard graph problems. For problems that are W[1]-hard parameterized by treewidth, a natural alternative would be to use a suitable…

Data Structures and Algorithms · Computer Science 2022-03-01 Cornelius Brand , Esra Ceylan , Christian Hatschka , Robert Ganian , Viktoriia Korchemna

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

Treewidth is a graph parameter of fundamental importance to algorithmic and structural graph theory. This paper surveys several graph parameters tied to treewidth, including separation number, tangle number, well-linked number and Cartesian…

Combinatorics · Mathematics 2016-01-29 Daniel J. Harvey , David R. Wood

We investigate a new width parameter, the fusion-width of a graph. It is a natural generalization of the tree-width, yet strong enough that not only graphs of bounded tree-width, but also graphs of bounded clique-width, trivially have…

Data Structures and Algorithms · Computer Science 2014-02-11 Martin Fürer

Quasi-trees generalize trees in that the unique "path" between two nodes may be infinite and have any countable order type. They are used to define the rank-width of a countable graph in such a way that it is equal to the least upper-bound…

Logic in Computer Science · Computer Science 2023-06-22 Bruno Courcelle

This paper studies the structure of graphs with given tree-width and excluding a fixed complete bipartite subgraph, which generalises the bounded degree setting. We give a new structural description of such graphs in terms of so-called…

Combinatorics · Mathematics 2025-12-15 Chun-Hung Liu , David R. Wood

We compute the treewidth of a family of graphs we refer to as the glued grids, consisting of the stacked prism graphs and the toroidal grids. Our main technique is constructing strict brambles of large orders. We discuss connections to…

Combinatorics · Mathematics 2019-11-05 Ivan Aidun , Frances Dean , Ralph Morrison , Teresa Yu , Julie Yuan

To most mathematicians and computer scientists the word ``tree'' conjures up, in addition to the usual image, the image of a connected graph with no circuits. In the last few years various types of trees have been the subject of much…

Group Theory · Mathematics 2016-09-06 John W. Morgan

Tree-cut width is a parameter that has been introduced as an attempt to obtain an analogue of treewidth for edge cuts. Unfortunately, in spite of its desirable structural properties, it turned out that tree-cut width falls short as an…

Computational Complexity · Computer Science 2022-07-01 Robert Ganian , Viktoriia Korchemna

We develop a purely set-theoretic formalism for binary trees and binary graphs. We define a category of binary automata, and display it as a fibred category over the category of binary graphs. We also relate the notion of binary graphs to…

Combinatorics · Mathematics 2007-05-23 N. Raghavendra

In Graph Minors III, Robertson and Seymour write: "It seems that the tree-width of a planar graph and the tree-width of its geometric dual are approximately equal - indeed, we have convinced ourselves that they differ by at most one". They…

Discrete Mathematics · Computer Science 2011-12-02 Frédéric Mazoit

Rank-width is a width parameter of graphs describing whether it is possible to decompose a graph into a tree-like structure by `simple' cuts. This survey aims to summarize known algorithmic and structural results on rank-width of graphs.

Combinatorics · Mathematics 2018-05-16 Sang-il Oum

Treewidth is a parameter that emerged from the study of minor closed classes of graphs (i.e. classes closed under vertex and edge deletion, and edge contraction). It in some sense describes the global structure of a graph. Roughly, a graph…

Combinatorics · Mathematics 2022-02-02 Tara Abrishami , Maria Chudnovsky , Kristina Vušković
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