scholarly journals Cubic graphs that cannot be covered with four perfect matchings

2021 ◽  
Vol 150 ◽  
pp. 144-176
Author(s):  
Edita Máčajová ◽  
Martin Škoviera
Author(s):  
Piotr Formanowicz ◽  
Krzysztof Tanaś

Abstract It was conjectured by Fan and Raspaud (1994) that every bridgeless cubic graph contains three perfect matchings such that every edge belongs to at most two of them. We show a randomized algorithmic way of finding Fan–Raspaud colorings of a given cubic graph and, analyzing the computer results, we try to find and describe the Fan–Raspaud colorings for some selected classes of cubic graphs. The presented algorithms can then be applied to the pair assignment problem in cubic computer networks. Another possible application of the algorithms is that of being a tool for mathematicians working in the field of cubic graph theory, for discovering edge colorings with certain mathematical properties and formulating new conjectures related to the Fan–Raspaud conjecture.


2014 ◽  
Vol 06 (02) ◽  
pp. 1450025 ◽  
Author(s):  
XIUMEI WANG ◽  
WEIPING SHANG ◽  
YIXUN LIN ◽  
MARCELO H. CARVALHO

The perfect matching polytope of a graph G is the convex hull of the incidence vectors of all perfect matchings in G. This paper characterizes claw-free cubic graphs whose 1-skeleton graphs of perfect matching polytopes have diameter 1.


2005 ◽  
Vol 22 ◽  
pp. 341-345 ◽  
Author(s):  
Tomáš Kaiser ◽  
Daniel Král' ◽  
Serguei Norine

10.37236/7175 ◽  
2019 ◽  
Vol 26 (1) ◽  
Author(s):  
Wuyang Sun ◽  
Fan Wang

A perfect matching cover of a graph $G$ is a set of perfect matchings of $G$ such that each edge of $G$ is contained in at least one member of it. Berge conjectured that every bridgeless cubic graph has a perfect matching cover of order at most 5. The Berge Conjecture is largely open and it is even unknown whether a constant integer $c$ does exist such that every bridgeless cubic graph has a perfect matching cover of order at most $c$. In this paper, we show that a bridgeless cubic graph $G$ has a perfect matching cover of order at most 11 if $G$ has a 2-factor in which the number of odd circuits is 2.


10.37236/549 ◽  
2011 ◽  
Vol 18 (1) ◽  
Author(s):  
Sang-il Oum

Lovász and Plummer conjectured that there exists a fixed positive constant $c$ such that every cubic $n$-vertex graph with no cutedge has at least $2^{cn}$ perfect matchings. Their conjecture has been verified for bipartite graphs by Voorhoeve and planar graphs by Chudnovsky and Seymour. We prove that every claw-free cubic $n$-vertex graph with no cutedge has more than $2^{n/12}$ perfect matchings, thus verifying the conjecture for claw-free graphs.


2009 ◽  
Vol 23 (3) ◽  
pp. 1465-1483 ◽  
Author(s):  
Daniel Král' ◽  
Jean-Sébastien Sereni ◽  
Michael Stiebitz

COMBINATORICA ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 61-94 ◽  
Author(s):  
Edita Máčajová ◽  
Martin Škoviera

Sign in / Sign up

Export Citation Format

Share Document