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Related papers: Triangle-Free Equimatchable Graphs

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A graph is called equimatchable if all of its maximal matchings have the same size. Due to Eiben and Kotrb\v{c}\'{i}k,, any connected graph with odd order and independence number $\alpha(G)$ at most $2$ is equimatchable. Akbari et al.…

Combinatorics · Mathematics 2025-09-15 Xiao Zhao , Haojie Zheng , Fengming Dong , Hengzhe Li , Yingbin Ma

A graph is equimatchable if all of its maximal matchings have the same size. A graph is claw-free if it does not have a claw as an induced subgraph. In this paper, we provide, to the best of our knowledge, the first characterization of…

Discrete Mathematics · Computer Science 2018-07-26 Saieed Akbari , Hadi Alizadeh , Tınaz Ekim , Didem Gözüpek , Mordechai Shalom

A graph $G$ is \emph{equimatchable} if every maximal matching of $G$ has the same cardinality. We are interested in equimatchable graphs such that the removal of any edge from the graph preserves the equimatchability. We call an…

Discrete Mathematics · Computer Science 2018-06-15 Zakir Deniz , Tınaz Ekim

A graph G is called well-indumatched if all of its maximal induced matchings have the same size. In this paper we characterize all well-indumatched trees. We provide a linear time algorithm to decide if a tree is well-indumatched or not.…

Discrete Mathematics · Computer Science 2019-12-18 S. Akbari , T. Ekim , A. H. Ghodrati , S. Zare

A matching covered graph $G$ is minimal if for each edge $e$ of $G$, $G-e$ is not matching covered. An edge $e$ of a matching covered graph $G$ is removable if $G-e$ is also matching covered. Thus a matching covered graph is minimal if and…

Combinatorics · Mathematics 2024-05-28 Yipei Zhang , Xiumei Wang , Jinjiang Yuan , C. T. Ng , T. C. E. Cheng

A graph is said to be equimatchable if all its maximal matchings are of the same size. In this work we introduce two extensions of the property of equimatchability by defining two new graph parameters that measure how far a graph is from…

Combinatorics · Mathematics 2016-12-28 Zakir Deniz , Tınaz Ekim , Tatiana Romina Hartinger , Martin Milanič , Mordechai Shalom

A hypergraph is called an r by r grid if it is isomorphic to a pattern of r horizontal and r vertical lines. Three sets form a triangle if they pairwise intersect in three distinct singletons. A hypergraph is linear if every pair of edges…

Combinatorics · Mathematics 2011-03-10 Zoltán Füredi , Miklós Ruszinkó

A maximal matching $M$ that consists of independent edges is a subgraph of a simple and undirected graph $G$ for which $G-M$ forms an independent set. A graph $G$ is called equimatchable if all maximal matchings have the same number of…

Combinatorics · Mathematics 2019-11-12 Mehmet Akif Yıldız

A graph is even-hole-free if it has no induced even cycles of length 4 or more. A cap is a cycle of length at least 5 with exactly one chord and that chord creates a triangle with the cycle. In this paper, we consider (cap, even hole)-free…

Discrete Mathematics · Computer Science 2016-11-28 Kathie Cameron , Murilo V. G. da Silva , Shenwei Huang , Kristina Vušković

Perfect Matching-Cut is the problem of deciding whether a graph has a perfect matching that contains an edge-cut. We show that this problem is NP-complete for planar graphs with maximum degree four, for planar graphs with girth five, for…

Combinatorics · Mathematics 2021-11-01 Valentin Bouquet , Christophe Picouleau

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

We consider a relaxation of the concept of well-covered graphs, which are graphs with all maximal independent sets of the same size. The extent to which a graph fails to be well-covered can be measured by its independence gap, defined as…

Discrete Mathematics · Computer Science 2023-06-22 Tınaz Ekim , Didem Gözüpek , Ademir Hujdurović , Martin Milanič

A graph G is equimatchable if every maximal matching of G has the same cardinality. In this paper, we investigate equimatchable graphs such that the removal of any edge harms the equimatchability, called edge-critical equimatchable graphs…

Combinatorics · Mathematics 2022-02-17 Zakir Deniz , Tınaz Ekim

We show that if $G$ is a simple triangle-free graph with $n\geq 3$ vertices, without a perfect matching, and having a minimum degree at least $\frac{n-1}{2}$, then $G$ is isomorphic either to $C_5$ or to $K_{\frac{n-1}{2},\frac{n+1}{2}}$.

Discrete Mathematics · Computer Science 2015-03-17 Vahan V. Mkrtchyan , Petros A. Petrosyan

An induced matching in a graph is a set of edges whose endpoints induce a $1$-regular subgraph. It is known that any $n$-vertex graph has at most $10^{n/5} \approx 1.5849^n$ maximal induced matchings, and this bound is best possible. We…

Combinatorics · Mathematics 2013-12-19 Manu Basavaraju , Pinar Heggernes , Pim van 't Hof , Reza Saei , Yngve Villanger

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

A matchstick graph is a graph drawn with straight edges in the plane such that the edges have unit length, and non-adjacent edges do not intersect. We call a matchstick graph $(m;n)$-regular if every vertex has only degree $m$ or $n$. In…

Combinatorics · Mathematics 2018-05-03 Mike Winkler , Peter Dinkelacker , Stefan Vogel

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

We revisit a classical paper about (even hole, triangle)-free graphs [Conforti, Cornu\'ejols, Kapoor and Vu\v skovi\'c, Triangle-free graphs that are signable without even holes, Journal of Graph Theory, 34(3), 204--220, 2000]. In fact, the…

Combinatorics · Mathematics 2026-04-03 Beatriz Martins , Nicolas Trotignon

An \emph{equitable coloring} of a graph is a proper vertex coloring such that the sizes of every two color classes differ by at most 1. Chen, Lih, and Wu conjectured that every connected graph $G$ with maximum degree $\Delta \geq 2$ has an…

Combinatorics · Mathematics 2012-03-05 Keaitsuda Nakprasit , Kittikorn Nakprasit
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