English
Related papers

Related papers: Product Dimension of Forests and Bounded Treewidth…

200 papers

Let $F(G)$ be the number of forests of a graph $G$. Similarly let $C(G)$ be the number of connected spanning subgraphs of a connected graph $G$. We bound $F(G)$ and $C(G)$ for regular graphs and for graphs with fixed average degree. Among…

Combinatorics · Mathematics 2021-08-03 Márton Borbényi , Péter Csikvári , Haoran Luo

A graph class $\mathcal{G}$ has linear growth if, for each graph $G \in \mathcal{G}$ and every positive integer $r$, every subgraph of $G$ with radius at most $r$ contains $O(r)$ vertices. In this paper, we show that every graph class with…

We introduce the notion of \emph{bounded diameter arboricity}. Specifically, the \emph{diameter-$d$ arboricity} of a graph is the minimum number $k$ such that the edges of the graph can be partitioned into $k$ forests each of whose…

Combinatorics · Mathematics 2016-08-19 Martin Merker , Luke Postle

A graph $G$ is universal for a class of graphs $\mathcal{C}$, if, up to isomorphism, $G$ contains every graph in $\mathcal{C}$ as a subgraph. In 1978, Chung and Graham asked for the minimal number $s(n)$ of edges in a graph with $n$…

Combinatorics · Mathematics 2026-03-27 Julian Becker , Konstantinos Panagiotou , Matija Pasch

Let $G = (V,w)$ be a weighted undirected graph with $m$ edges. The cut dimension of $G$ is the dimension of the span of the characteristic vectors of the minimum cuts of $G$, viewed as vectors in $\{0,1\}^m$. For every $n \ge 2$ we show…

Computational Complexity · Computer Science 2020-11-30 Troy Lee , Tongyang Li , Miklos Santha , Shengyu Zhang

An induced forest of a graph G is an acyclic induced subgraph of G. The present paper is devoted to the analysis of a simple randomised algorithm that grows an induced forest in a regular graph. The expected size of the forest it outputs…

Combinatorics · Mathematics 2007-09-21 Carlos Hoppen , Nicholas Wormald

Let v(G) be the number of vertices and t(G,k) the maximum number of disjoint k-edge trees in G. In this paper we show that (a1) if G is a graph with every vertex of degree at least two and at most s, where s > 3, then t(G,2) is at least…

Combinatorics · Mathematics 2007-05-23 Alexander Kelmans

We give an algorithm that for an input n-vertex graph G and integer k>0, in time 2^[O(k)]n either outputs that the treewidth of G is larger than k, or gives a tree decomposition of G of width at most 5k+4. This is the first algorithm…

Data Structures and Algorithms · Computer Science 2013-04-24 Hans Bodlaender , Pål G. Drange , Markus S. Dregi , Fedor V. Fomin , Daniel Lokshtanov , Michał Pilipczuk

A linear forest is an acyclic graph whose each connected component is a path; or in other words, it is an acyclic graph whose maximum degree is at most 2. A linear coloring of a graph $G$ is an edge coloring of $G$ such that the edges in…

Combinatorics · Mathematics 2023-08-16 Manu Basavaraju , Arijit Bishnu , Mathew Francis , Drimit Pattanayak

We discuss how to find the well-covered dimension of a graph that is the Cartesian product of paths, cycles, complete graphs, and other simple graphs. Also, a bound for the well-covered dimension of $K_n\times G$ is found, provided that $G$…

Combinatorics · Mathematics 2015-03-13 Isaac Birnbaum , Megan Kuneli , Robyn McDonald , Katherine Urabe , Oscar Vega

Phylogenetic trees and networks are leaf-labelled graphs used to model evolution. Display graphs are created by identifying common leaf labels in two or more phylogenetic trees or networks. The treewidth of such graphs is bounded as a…

Data Structures and Algorithms · Computer Science 2018-09-05 Remie Janssen , Mark Jones , Steven Kelk , Georgios Stamoulis , Taoyang Wu

Let $G$ be a graph, and let $u$, $v$, and $w$ be vertices of $G$. If the distance between $u$ and $w$ does not equal the distance between $v$ and $w$, then $w$ is said to resolve $u$ and $v$. The metric dimension of $G$, denoted $\beta(G)$,…

Combinatorics · Mathematics 2020-01-28 Lucas Mol , Matthew J. H. Murphy , Ortrud R. Oellermann

An L(2, 1)-labeling of a graph is an assignment of nonnegative integers to the vertices of G such that adjacent vertices receive numbers differed by at least 2, and vertices at distance 2 are assigned distinct numbers. The L(2, 1)-labeling…

Combinatorics · Mathematics 2015-09-02 Dong Chen , Wai Chee Shiu , Qiaojun Shu , Pak Kiu Sun , Weifan Wang

We give here new upper bounds on the size of a smallest feedback vertex set in planar graphs with high girth. In particular, we prove that a planar graph with girth $g$ and size $m$ has a feedback vertex set of size at most $\frac{4m}{3g}$,…

Discrete Mathematics · Computer Science 2015-04-09 François Dross , Mickael Montassier , Alexandre Pinlou

Alon, Seymour and Thomas [1990] proved that every $n$-vertex graph excluding $K_t$ as a minor has treewidth less than $t^{3/2}\sqrt{n}$. Illingworth, Scott and Wood [2022] recently refined this result by showing that every such graph is a…

This paper shows that $K_t$-minor-free (and $K_{s, t}$-minor-free) graphs $G$ are subgraphs of products of a tree-like graph $H$ (of bounded treewidth) and a complete graph $K_m$. Our results include optimal bounds on the treewidth of $H$…

Combinatorics · Mathematics 2024-11-11 Freddie Illingworth , Alex Scott , David R. Wood

Dujmovi\'c, Joret, Micek, Morin, Ueckerdt and Wood [J. ACM 2020] proved that for every planar graph $G$ there is a graph $H$ with treewidth at most 8 and a path $P$ such that $G\subseteq H\boxtimes P$. We improve this result by replacing…

Combinatorics · Mathematics 2021-08-21 Torsten Ueckerdt , David R. Wood , Wendy Yi

For an ordered subset $S = \{s_1, s_2,\dots s_k\}$ of vertices and a vertex $u$ in a connected graph $G$, the metric representation of $u$ with respect to $S$ is the ordered $k$-tuple $ r(u|S)=(d_G(v,s_1), d_G(v,s_2),\dots,$ $d_G(v,s_k))$,…

Combinatorics · Mathematics 2015-09-08 Juan A. Rodriguez-Velazquez , Dorota Kuziak , Ismael G. Yero , Jose M. Sigarreta

The metric dimension of a graph G is the minimum size of a subset S of vertices of G such that all other vertices are uniquely determined by their distances to the vertices in S. In this paper we investigate the metric dimension for two…

Combinatorics · Mathematics 2014-12-09 Dieter Mitsche , Juanjo Rué

For a graph $G$, let $c_k(G)$ be the number of spanning trees of $G$ with maximum degree at most $k$. For $k \ge 3$, it is proved that every connected $n$-vertex $r$-regular graph $G$ with $r \ge \frac{n}{k+1}$ satisfies $$ c_k(G)^{1/n} \ge…

Combinatorics · Mathematics 2022-08-01 Raphael Yuster