English
Related papers

Related papers: Weighted Well-Covered Claw-Free Graphs

200 papers

A matching in a bipartite graph with parts X and Y is called envy-free if no unmatched vertex in X is a adjacent to a matched vertex in Y. Every perfect matching is envy-free, but envy-free matchings exist even when perfect matchings do…

Data Structures and Algorithms · Computer Science 2022-04-15 Elad Aigner-Horev , Erel Segal-Halevi

In this paper, we study graphs whose matching polynomial have only integer zeros. A graph is matching integral if the zeros of its matching polynomial are all integers. We characterize all matching integral traceable graphs.. We show that…

Combinatorics · Mathematics 2017-02-07 S. Akbari , P. Csikvari , A. Ghafari , S. Khalashi Ghezelahmad , M. Nahvi

The Connected Vertex Cover problem is to decide if a graph G has a vertex cover of size at most $k$ that induces a connected subgraph of $G$. This is a well-studied problem, known to be NP-complete for restricted graph classes, and, in…

Data Structures and Algorithms · Computer Science 2018-07-06 Matthew Johnson , Giacomo Paesani , Daniel Paulusma

A graph is called claw-free if it contains no induced subgraph isomorphic to the complete bipartite graph $K_{1, 3}$. The undirected power graph of a group $G$ has vertices the elements of $G$, with an edge between $g_1$ and $g_2$ if one of…

Group Theory · Mathematics 2024-07-30 Pallabi Manna , Santanu Mandal , Andrea Lucchini

If $L$ is a list assignment of $r$ colors to each vertex of an $n$-vertex graph $G$, then an equitable $L$-coloring of $G$ is a proper coloring of vertices of $G$ from their lists such that no color is used more than $\lceil n/r\rceil$…

Combinatorics · Mathematics 2023-09-08 H. A. Kierstead , Alexandr Kostochka , Zimu Xiang

A very well-covered graph is a well-covered graph without isolated vertices such that the size of its minimal vertex covers is half of the number of vertices. If $G$ is a Cohen-Macaulay very well-covered graph, we deeply investigate some…

Commutative Algebra · Mathematics 2023-06-13 Marilena Crupi , Antonino Ficarra

A graph is equimatchable if each of its matchings is a subset of a maximum matching. It is known that any 2-connected equimatchable graph is either bipartite, or factor-critical, and that these two classes are disjoint. This paper provides…

Combinatorics · Mathematics 2015-01-30 Eduard Eiben , Michal Kotrbcik

The independence polynomial $i(G,x)$ of a graph $G$ is the generating function of the numbers of independent sets of each size. A graph of order $n$ is very well-covered if every maximal independent set has size $n/2$. Levit and Mandrescu…

Combinatorics · Mathematics 2017-09-26 Jason I. Brown , Ben Cameron

We show that for each single crossing graph $H$, a polynomially bounded weight function for all $H$-minor free graphs $G$ can be constructed in Logspace such that it gives nonzero weights to all the cycles in $G$. This class of graphs…

Computational Complexity · Computer Science 2021-09-07 Samir Datta , Chetan Gupta , Rahul Jain , Anish Mukherjee , Vimal Raj Sharma , Raghunath Tewari

As usual, $P_n$ ($n \geq 1$) denotes the path on $n$ vertices, and $C_n$ ($n \geq 3$) denotes the cycle on $n$ vertices. For a family $\mathcal{H}$ of graphs, we say that a graph $G$ is $\mathcal{H}$-free if no induced subgraph of $G$ is…

Combinatorics · Mathematics 2018-03-12 Kathie Cameron , Shenwei Huang , Irena Penev , Vaidy Sivaraman

A perfect matching in an undirected graph $G=(V,E)$ is a set of vertex disjoint edges from $E$ that include all vertices in $V$. The perfect matching problem is to decide if $G$ has such a matching. Recently Rothvo{\ss} proved the striking…

Discrete Mathematics · Computer Science 2018-04-26 David Avis , David Bremner , Hans Raj Tiwary , Osamu Watanabe

Given a graph $G$, a set $F$ of edges is an edge dominating set if all edges in $G$ are either in $F$ or adjacent to an edge in $F$. $G$ is said to be well-edge-dominated if every minimal edge dominating set is also minimum. In 2022, it was…

Combinatorics · Mathematics 2026-01-08 Sarah E. Anderson , Kirsti Kuenzel

A graph homomorphism is a vertex map which carries edges from a source graph to edges in a target graph. The instances of the Weighted Maximum H-Colourable Subgraph problem (MAX H-COL) are edge-weighted graphs G and the objective is to find…

Discrete Mathematics · Computer Science 2009-11-18 Robert Engström , Tommy Färnqvist , Peter Jonsson , Johan Thapper

Given two graphs $G_1$ and $G_2$ on $n$ vertices each, we define a graph $G$ on vertex set $V_1\times V_2$ and the edge set as the union of edges of $G_1\times \bar{G_2}$, $\bar{G_1}\times G_2$, $\{(v,u'),(v,u"))(|u',u"\in V_2\}$ for each…

Data Structures and Algorithms · Computer Science 2013-01-14 Shashank K Mehta , Pawan Aurora

We consider a weighted counting problem on matchings, denoted $\textrm{PrMatching}(\mathcal{G})$, on an arbitrary fixed graph family $\mathcal{G}$. The input consists of a graph $G\in \mathcal{G}$ and of rational probabilities of existence…

Computational Complexity · Computer Science 2023-01-10 Antoine Amarilli , Mikaël Monet

A graph $G$ is total weight $(k,k')$-choosable if for any total list assignment $L$ which assigns to each vertex $v$ a set $L(v)$ of $k$ real numbers, and each edge $e$ a set $L(e)$ of $k'$ real numbers, there is a proper total…

Combinatorics · Mathematics 2022-02-22 Huajing Lu , Xuding Zhu

Given a graph $G$, the graph $[G]$ obtained by adding, for each pair of vertices of $G$, a unique vertex adjacent to both vertices is called the binding graph of $G$. In this work, we show that the class of binding graphs is…

Combinatorics · Mathematics 2024-08-27 Rui Xue

A set S of vertices is independent in a graph G if no two vertices from S are adjacent, and alpha(G) is the cardinality of a maximum independent set of G. G is called a Konig-Egervary graph if its order equals alpha(G)+mu(G), where mu(G)…

Discrete Mathematics · Computer Science 2011-02-08 Vadim E. Levit , Eugen Mandrescu

A graph $G$ is equimatchable if any matching in $G$ is a subset of a maximum-size matching. It is known that any $2$-connected equimatchable graph is either bipartite or factor-critical. We prove that for any vertex $v$ of a $2$-connected…

Combinatorics · Mathematics 2013-12-13 Eduard Eiben , Michal Kotrbčík

A graph $G$ is perfectly divisible if, for every induced subgraph $H$ of $G$, either $V(H)$ is a stable set or admits a partition into two sets $X_1$ and $X_2$ such that $\omega(H[X_1]) < \omega(H)$ and $H[X_2]$ is a perfect graph. In this…

Combinatorics · Mathematics 2025-04-30 David Scholz