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Related papers: Covering a cubic graph with perfect matchings

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We present an algorithm for finding a perfect matching in a $3$-edge-connected cubic graph that intersects every $3$-edge cut in exactly one edge. Specifically, we propose an algorithm with a time complexity of $O(n \log^4 n)$, which…

Data Structures and Algorithms · Computer Science 2025-07-03 Babak Ghanbari , Robert Šámal

Let $G$ be a simple graph with $2n$ vertices and a perfect matching. We denote by $f(G)$ and $F(G)$ the minimum and maximum forcing number of $G$, respectively. Hetyei obtained that the maximum number of edges of graphs $G$ with a unique…

Combinatorics · Mathematics 2022-11-23 Qianqian Liu , Heping Zhang

Let $G$ be a bridgeless cubic graph. Consider a list of $k$ 1-factors of $G$. Let $E_i$ be the set of edges contained in precisely $i$ members of the $k$ 1-factors. Let $\mu_k(G)$ be the smallest $|E_0|$ over all lists of $k$ 1-factors of…

Combinatorics · Mathematics 2015-09-22 Eckhard Steffen

A graph whose vertices are points in the plane and whose edges are noncrossing straight-line segments of unit length is called a \emph{matchstick graph}. We prove two somewhat counterintuitive results concerning the maximum number of edges…

Combinatorics · Mathematics 2025-06-03 Panna Gehér , János Pach , Konrad Swanepoel , Géza Tóth

We study the following problem - How many arbitrary edges can be removed from a complete geometric graph with 2n vertices such that the resulting graph always contains a perfect non-crossing matching? We first address the case where the…

Combinatorics · Mathematics 2025-01-17 Aviv Sheyn , Ran J. Tessler

A bisection of a graph is a bipartition of its vertex set such that the two resulting parts differ in size by at most 1, and its size is the number of edges that connect vertices in the two parts. The perfect matching condition and…

Combinatorics · Mathematics 2024-11-19 Jianfeng Hou , Shufei Wu , Yuanyuan Zhong

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

A perfect matching in a graph $G$ is a set of nonadjacent edges covering every vertex of $G$. Motivated by recent progress on the relations between the eigenvalues and the matching number of a graph, in this paper, we aim to present a…

Combinatorics · Mathematics 2021-01-13 Yuke Zhang , Huiqiu Lin

A perfect matching in a 4-uniform hypergraph is a subset of $\lfloor\frac{n}{4}\rfloor$ disjoint edges. We prove that if $H$ is a sufficiently large 4-uniform hypergraph on $n=4k$ vertices such that every vertex belongs to more than…

Discrete Mathematics · Computer Science 2015-03-18 Imdadullah Khan

{ An edge $e$ in a matching covered graph $G$ is {\em removable} if $G-e$ is matching covered, which was introduced by Lov\'asz and Plummer in connection with ear decompositions of matching covered graphs. A {\it brick}} is a non-bipartite…

Combinatorics · Mathematics 2024-01-17 Lu Fuliang , Qian Jianguo

We study separating matchings in graphs, that is, matchings whose removal increases the number of connected components, and focus on determining the maximum size of such a matching in a graph $G$, denoted by $\mathrm{mms}(G)$. We show that…

Combinatorics · Mathematics 2026-04-21 Juan Gutiérrez , Renzo Gómez

A normal $k$-edge-coloring of a cubic graph is an edge-coloring with $k$ colors having the additional property that when looking at the set of colors assigned to any edge $e$ and the four edges adjacent it, we have either exactly five…

Discrete Mathematics · Computer Science 2021-10-05 Giuseppe Mazzuoccolo , Vahan Mkrtchyan

We show that every bridgeless cubic graph $G$ with $m$ edges has a cycle cover of length at most $1.6 m$. Moreover, if $G$ does not contain any intersecting circuits of length $5$, then $G$ has a cycle cover of length $212/135 \cdot m…

Combinatorics · Mathematics 2015-09-25 Barbora Candráková , Robert Lukoťka

All the work made so far on edge-covering a graph by cliques focus on finding the minimum number of cliques that cover the graph. On this paper, we fix the number of cliques that cover a graph by the same number of vertices that the graph…

Combinatorics · Mathematics 2017-03-09 Leopoldo Taravilse

In this note, we determine the maximum number of edges of a $k$-uniform hypergraph, $k\ge 3$, with a unique perfect matching. This settles a conjecture proposed by Snevily.

Combinatorics · Mathematics 2011-07-11 Deepak Bal , Andrzej Dudek , Zelealem B. Yilma

A vertex $v$ of a 2-connected cubic graph $G$ is $\lambda$-matchable if $G$ has a spanning subgraph in which $v$ has degree three whereas every other vertex has degree one, and we let $\lambda(G)$ denote the number of such vertices.…

Combinatorics · Mathematics 2025-10-15 Santhosh Raghul , Nishad Kothari

We consider three variants of the problem of finding a maximum weight restricted $2$-matching in a subcubic graph $G$. (A $2$-matching is any subset of the edges such that each vertex is incident to at most two of its edges.) Depending on…

Data Structures and Algorithms · Computer Science 2021-01-01 Katarzyna Paluch , Mateusz Wasylkiewicz

A graph is {\em perfect} if, in all its induced subgraphs, the size of a largest clique is equal to the chromatic number. Examples of perfect graphs include bipartite graphs, line graphs of bipartite graphs and the complements of such…

Combinatorics · Mathematics 2007-05-23 Gérard Cornuéjols

The smallest number of cliques, covering all edges of a graph $ G $, is called the (edge) clique cover number of $ G $ and is denoted by $ cc(G) $. It is an easy observation that for every line graph $ G $ with $ n $ vertices, $cc(G)\leq n…

Combinatorics · Mathematics 2023-09-06 Ramin Javadi , Sepehr Hajebi

Petersen's theorem, one of the earliest results in graph theory, states that any bridgeless cubic multigraph contains a perfect matching. While the original proof was neither constructive nor algorithmic, Biedl, Bose, Demaine, and Lubiw [J.…

Data Structures and Algorithms · Computer Science 2024-05-08 Paweł Gawrychowski , Mateusz Wasylkiewicz