Results 81 to 90 of about 113,121 (99)

Vizing’s conjecture: A two-thirds bound for claw-free graphs

open access: yesDiscrete Applied Mathematics, 2017
We show that for any claw-free graph $G$ and any graph $H$, $γ(G\square H)\geq \frac{2}{3}γ(G)γ(H)$, where $γ(G)$ is the domination number of $G$.
openaire   +3 more sources

Vizing's Conjecture for Graphs with Domination Number 3 - a New Proof

open access: yesThe Electronic Journal of Combinatorics, 2015
Vizing's conjecture from 1968 asserts that the domination number of the Cartesian product of two graphs is at least as large as the product of their domination numbers. In this note we use a new, transparent approach to prove Vizing's conjecture for graphs with domination number 3;  that is, we prove that for any graph $G$ with $\gamma(G)=3$ and an ...
openaire   +3 more sources

On two conjectures to generalize Vizing's theorem

open access: yesLe Matematiche, 1990
Summary: Vizing's theorem states that for a simple graph \(G\), the chromatic index \(q(G)\) is equal to the maximum degree \(\Delta(G)\) or to \(\Delta(G)+1\). To extend this theorem to some classes of hypergraphs, we suggested two conjectures, non-comparable, but, in some sense, dual, which are discussed in the present paper.
openaire   +2 more sources

A brief, simple proof of Vizing's conjecture

open access: yes, 2011
This paper has been withdrawn by the author due to a problem with the "label exchange"
openaire   +2 more sources

On Convex Subcomplexes of Spherical Buildings and Tits’ Center Conjecture [PDF]

open access: yes, 2009
In this thesis we study convex subcomplexes of spherical buildings. In particular, we are interested in a question of J. Tits which goes back to the 50’s, the so-called Center Conjecture.
Ramos Cuevas, Carlos
core   +1 more source

Supermodular Extension of Vizing's Edge-Coloring Theorem [PDF]

open access: yes
K\H{o}nig's edge-coloring theorem for bipartite graphs and Vizing's edge-coloring theorem for general graphs are celebrated results in graph theory and combinatorial optimization.
Mizutani, Ryuhei
core   +1 more source

Vizing's conjecture: a survey and recent results

open access: yes, 2012
Vizingova domneva iz leta 1968 trdi, da je dominacijsko število kartezičnega produkta dveh grafov vsaj tako veliko, kot je produkt dominacijskih števil faktorjev. V članku naredimo pregled različnih pristopov k tej osrednji domnevi iz teorije grafovske dominacije. Ob tem dokažemo tudi nekaj novih rezultatov.
Brešar, Boštjan   +6 more
openaire   +1 more source

A partition approach to Vizing's conjecture

Journal of Graph Theory, 1996
One conjecture of V. G. Vizing says that \(\gamma(G\times H)\geq \gamma(G) \gamma(H)\), where \(\gamma\) is the domination number of a graph. The authors prove the inequalities \(P_2(G)\leq x(G)\leq \gamma(G)\) and \(\gamma(G\times H)\geq x(G) \gamma(H)\). The symbol \(P_2(G)\) denotes the 2-packing number of \(G\), i.e.
Guantao Chen   +2 more
openaire   +3 more sources

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