English
Related papers

Related papers: On Generalizations of Pairwise Compatibility Graph…

200 papers

Property $(P)$, introduced in recent work and rooted in the classical theory of Parter vertices, concerns the existence of a nonsingular matrix $A\in S(G)$ for which every vertex of $G$ is a $P$-vertex. Previous investigations have fully…

Combinatorics · Mathematics 2025-12-12 G. Arunkumar , Puja Samanta

A path $P$ in an edge-colored graph $G$ is a \emph{proper path} if no two adjacent edges of $P$ are colored with the same color. The graph $G$ is \emph{proper connected} if, between every pair of vertices, there exists a proper path in $G$.…

Combinatorics · Mathematics 2016-11-30 Hong Chang , Zhong Huang , Xueliang Li

An independent edge set of graph $G$ is a matching, and is maximal if it is not a proper subset of any other matching of $G$. The number of all the maximal matchings of $G$ is denoted by $\Psi(G)$. In this paper, an algorithm to count…

Combinatorics · Mathematics 2025-06-11 Lingjuan Shi , Wei Li , Kai Deng

A plane topological graph $G=(V,E)$ is a graph drawn in the plane whose vertices are points in the plane and whose edges are simple curves that do not intersect, except at their endpoints. Given a plane topological graph $G=(V,E)$ and a set…

Computational Geometry · Computer Science 2020-07-24 J. C. Catana , A. García , J. Tejel , J. Urrutia

We define the following parameter of connected graphs. For a given graph $G$ we place one agent in each vertex of $G$. Every pair of agents sharing a common edge is declared to be acquainted. In each round we choose some matching of $G$…

Computational Complexity · Computer Science 2014-03-14 Itai Benjamini , Igor Shinkar , Gilad Tsur

A graph $G$ is called $B_k$-VPG, for some constant $k\geq 0$, if it has a string representation on an axis-parallel grid such that each vertex is a path with at most $k$ bends and two vertices are adjacent in $G$ if and only if the…

Computational Geometry · Computer Science 2018-09-10 Saeed Mehrabi

In this work, we relate girth and path-degeneracy in classes with sub-exponential expansion, with explicit bounds for classes with polynomial expansion and proper minor-closed classes that are tight up to a constant factor (and tight up to…

Combinatorics · Mathematics 2025-03-25 Y. Lin , P. Ossona de Mendez

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 path in an edge-colored graph is called a proper path if no two adjacent edges of the path receive the same color. For a connected graph $G$, the proper connection number $pc(G)$ of $G$ is defined as the minimum number of colors needed to…

Combinatorics · Mathematics 2016-02-25 Fei Huang , Xueliang Li , Zhongmei Qin , Colton Magnant

Let $G$ be an edge-colored connected graph. A path $P$ in $G$ is called a distance $\ell$-proper path if no two edges of the same color appear with fewer than $\ell$ edges in between on $P$. The graph $G$ is called $(k,\ell)$-proper…

Combinatorics · Mathematics 2016-06-22 Xueliang Li , Colton Magnant , Meiqin Wei , Xiaoyu Zhu

THIS IS A CORRECTED VERSION INCLUDING AN APPENDED CORRIGENDUM. Best match graphs arise naturally as the first processing intermediate in algorithms for orthology detection. Let $T$ be a phylogenetic (gene) tree $T$ and $\sigma$ an…

An edge (vertex) cut $X$ of $G$ is $r$-essential if $G-X$ has two components each of which has at least $r$ edges. A graph $G$ is $r$-essentially $k$-edge-connected (resp. $k$-connected) if it has no $r$-essential edge (resp. vertex) cuts…

Combinatorics · Mathematics 2022-08-30 Xiaofeng Gu , Runrun Liu , Gexin Yu

Let $\mathcal{G}$ be the set of simple graphs (or multigraphs) $G$ such that for each $G \in \mathcal{G}$ there exists at least two non-empty disjoint proper subsets $V_{1},V_{2}\subseteq V(G)$ satisfying $V(G)\setminus(V_{1} \cup…

Combinatorics · Mathematics 2018-11-19 Cunxiang Duan , Ligong Wang , Xiangxiang Liu

Given a function $p : V(G)\to \mathbb N$ and an integer $k\ge 0$, define $p_k(G)$ as the number of vertices with $p(v)\ge k$. We say that $p_k(G)$ is bounded for all $\HH$-free graphs if there exists a constant $c=c(\HH)$ such that…

Combinatorics · Mathematics 2025-12-05 Jin Sun , Xinmin Hou

The three well-known graph classes, planar graphs (P), series-parallel graphs(SP) and outer planar graphs(OP) satisfy the following proper inclusion relation: OP C SP C P. It is known that box(G) <= 3 if G belongs to P and box(G) <= 2 if G…

Combinatorics · Mathematics 2007-05-23 Ankur Bohra , L. Sunil Chandran , J. Krishnam Raju

The concept of $k$-planarity is extensively studied in the context of Beyond Planarity. A graph is $k$-planar if it admits a drawing in the plane in which each edge is crossed at most $k$ times. The local crossing number of a graph is the…

Data Structures and Algorithms · Computer Science 2025-08-28 Tatsuya Gima , Yasuaki Kobayashi , Yuto Okada

A path in an edge-colored graph is called a proper path if no two adjacent edges of the path are colored with one same color. An edge-colored graph is called $k$-proper connected if any two vertices of the graph are connected by $k$…

Combinatorics · Mathematics 2015-07-13 Fei Huang , Xueliang Li , Shujing Wang

The \emph{spanning tree packing number} of a graph $G$ is the maximum number of edge-disjoint spanning trees contained in $G$. Let $k\geq 1$ be a fixed integer. Palmer and Spencer proved that in almost every random graph process, the…

Combinatorics · Mathematics 2013-01-08 Xiaolin Chen , Xueliang Li , Huishu Lian

An edge-colored graph $G$ is \emph{conflict-free connected} if any two of its vertices are connected by a path, which contains a color used on exactly one of its edges. The \emph{conflict-free connection number} of a connected graph $G$,…

Combinatorics · Mathematics 2018-05-09 Hong Chang , Trung Duy Doan , Zhong Huang , Stanislav Jendrol' , Xueliang Li , Ingo Schiermeyer

The clique graph $kG$ of a graph $G$ has as its vertices the cliques (maximal complete subgraphs) of $G$, two of which are adjacent in $kG$ if they have non-empty intersection in $G$. We say that $G$ is clique convergent if $k^nG\cong k^m…

Combinatorics · Mathematics 2025-01-03 Anna M. Limbach , Martin Winter