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A partition approach to Vizing's conjecture

✍ Scribed by Chen, Guantao; Piotrowski, Wiktor; Shreve, Warren


Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
411 KB
Volume
21
Category
Article
ISSN
0364-9024

No coin nor oath required. For personal study only.

✦ Synopsis


In 1963, Vizing [Vichysl. Sistemy 9 (19631, 30-431

conjectured that y ( G X H) 2 y ( G ) y ( H ) , where G X Hdenotes the Cartesian product of graphs, and y(G) is the domination number. In this paper we define the extraction number x(G) and w e prove that

M G ) 5 x(G) 5 y(G), and y ( G x H) 2 x(G)y(H),

where Pz(G) is the 2-packing number of G. Though the equality x(G) = y(G) is proven to hold in several classes of graphs, w e construct an infinite family of graphs which do not satisfy this condition. Also, we show the following lower bound: y ( G X H) 2 y(G)Pz(H) + Pz(G) ( y ( H ) -P,(H)).


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