English
Related papers

Related papers: Boxicity of Series Parallel Graphs

200 papers

Boxicity of a graph $G(V,$ $E)$, denoted by $box(G)$, is the minimum integer $k$ such that $G$ can be represented as the intersection graph of axis parallel boxes in $\mathbb{R}^k$. The problem of computing boxicity is inapproximable even…

Data Structures and Algorithms · Computer Science 2014-03-06 Abhijin Adiga , Jasine Babu , L. Sunil Chandran

The 'boxicity' ('cubicity') of a graph G is the minimum natural number k such that G can be represented as an intersection graph of axis-parallel rectangular boxes (axis-parallel unit cubes) in $R^k$. In this article, we give estimates on…

Combinatorics · Mathematics 2013-05-23 L. Sunil Chandran , Wilfried Imrich , Rogers Mathew , Deepak Rajendraprasad

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

Boxicity of a graph $G(V,E)$ is the minimum integer $k$ such that $G$ can be represented as the intersection graph of $k$-dimensional axis parallel rectangles in $\mathbf{R}^k$. Equivalently, it is the minimum number of interval graphs on…

Data Structures and Algorithms · Computer Science 2011-02-09 Abhijin Adiga , Jasine Babu , L. Sunil Chandran

Given finitely many connected polygonal obstacles $O_1,\dots,O_k$ in the plane and a set $P$ of points in general position and not in any obstacle, the {\em visibility graph} of $P$ with obstacles $O_1,\dots,O_k$ is the (geometric) graph…

Combinatorics · Mathematics 2017-09-08 John Gimbel , Patrice Ossona de Mendez , Pavel Valtr

A graph $G$ is a pairwise compatibility graph (PCG) if there exists an edge-weighted tree and an interval $I$, such that each leaf of the tree is a vertex of the graph, and there is an edge $\{ x, y \}$ in $G$ if and only if the weight of…

Combinatorics · Mathematics 2024-10-09 Tiziana Calamoneri , Manuel Lafond , Angelo Monti , Blerina Sinaimeri

A $k$-box $B=(R_1,...,R_k)$, where each $R_i$ is a closed interval on the real line, is defined to be the Cartesian product $R_1\times R_2\times ...\times R_k$. If each $R_i$ is a unit length interval, we call $B$ a $k$-cube. Boxicity of a…

Combinatorics · Mathematics 2012-01-31 Abhijin Adiga , L. Sunil Chandran , Rogers Mathew

The vertex arboricity $a(G)$ of a graph $G$ is the minimum $k$ such that $V(G)$ can be partitioned into $k$ sets where each set induces a forest. For a planar graph $G$, it is known that $a(G)\leq 3$. In two recent papers, it was proved…

Combinatorics · Mathematics 2013-04-09 Ilkyoo Choi , Haihui Zhang

A \emph{tree-partition} of a graph $G$ is a proper partition of its vertex set into `bags', such that identifying the vertices in each bag produces a forest. The \emph{tree-partition-width} of $G$ is the minimum number of vertices in a bag…

Combinatorics · Mathematics 2009-04-02 David R. Wood

Let $G$ be a nontrivial connected graph of order $n$ and let $k$ be an integer with $2\leq k\leq n$. For a set $S$ of $k$ vertices of $G$, let $\kappa (S)$ denote the maximum number $\ell$ of edge-disjoint trees $T_1,T_2,...,T_\ell$ in $G$…

Combinatorics · Mathematics 2009-06-18 Shasha Li , Xueliang Li , Wenli Zhou

A graph is $k$-planar $(k \geq 1)$ if it can be drawn in the plane such that no edge is crossed more than $k$ times. A graph is $k$-quasi planar $(k \geq 2)$ if it can be drawn in the plane with no $k$ pairwise crossing edges. The families…

The \emph{local boxicity} of a graph $G$, denoted by $lbox(G)$, is the minimum positive integer $l$ such that $G$ can be obtained using the intersection of $k$ (, where $k \geq l$,) interval graphs where each vertex of $G$ appears as a…

Combinatorics · Mathematics 2022-01-26 Atrayee Majumder , Rogers Mathew

The treewidth is a structural parameter that measures the tree-likeness of a graph. Many algorithmic and combinatorial results are expressed in terms of the treewidth. In this paper, we study the treewidth of outer $k$-planar graphs, that…

Discrete Mathematics · Computer Science 2025-04-24 Oksana Firman , Grzegorz Gutowski , Myroslav Kryven , Yuto Okada , Alexander Wolff

The linear arboricity la(G) of a graph G is the minimum number of linear forests that partition the edges of G. In 1984, Akiyama et al. stated the Linear Arboricity Conjecture (LAC), that the linear arboricity of any simple graph of maximum…

Combinatorics · Mathematics 2012-09-06 Marek Cygan , Lukasz Kowalik , Borut Luzar

Linear rank-width is a graph width parameter, which is a variation of rank-width by restricting its tree to a caterpillar. As a corollary of known theorems, for each $k$, there is a finite obstruction set $\mathcal{O}_k$ of graphs such that…

Combinatorics · Mathematics 2014-09-10 Jisu Jeong , O-joung Kwon , Sang-il Oum

A $k$-dimensional box is the cartesian product $R_1 \times R_2 \times ... \times R_k$ where each $R_i$ is a closed interval on the real line. The {\it boxicity} of a graph $G$, denoted as $box(G)$, is the minimum integer $k$ such that $G$…

Combinatorics · Mathematics 2007-12-18 L. Sunil Chandran , Anita Das , Chintan Shah

A box in Euclidean $k$-space is the Cartesian product $I_1\times I_2\times \cdots \times I_k$, where $I_j$ is a closed interval on the real line. The boxicity of a graph $G$, denoted by $\text{box}(G)$, is the minimum nonnegative integer…

Combinatorics · Mathematics 2015-08-06 Akira Kamibeppu

A bipartite graph $G = (X \cup Y, E)$ is a 2-layer $k$-planar graph if it admits a drawing on the plane such that the vertices in $X$ and $Y$ are placed on two parallel lines respectively, edges are drawn as straight-line segments, and…

Discrete Mathematics · Computer Science 2026-02-20 Yuto Okada

The boxicity of a graph $G=(V,E)$ is the smallest integer $k$ for which there exist $k$ interval graphs $G_i=(V,E_i)$, $1 \le i \le k$, such that $E=E_1 \cap \cdots \cap E_k$. In the first part of this note, we prove that every graph on $m$…

Combinatorics · Mathematics 2015-09-01 Louis Esperet

Consider the following problem: Given a planar graph $G$, what is the maximum number $p$ such that $G$ has a planar straight-line drawing with $p$ collinear vertices? This problem resides at the core of several graph drawing problems,…

Computational Geometry · Computer Science 2016-09-01 Giordano Da Lozzo , Vida Dujmovic , Fabrizio Frati , Tamara Mchedlidze , Vincenzo Roselli