arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.01909math.CO
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关于图的笛卡儿积的全控制

On total domination in the Cartesian product of graphs

Boštjan Brešar, Tatiana Romina Hartinger, Tim Kos, Martin Milanič

摘要:

Ho在[A note on the total dominance number,Util.Math. 77(2008)97- 100]中证明了任意两个没有孤立点的图的笛卡儿积的总控制数至少是它们的总控制数之积的一半。本文推广了Lu和Hou在[图与$K_2$或$C_n$的笛卡儿积的全控制,Util. Math.83(2010)313- 322],通过表征图对$G$和$H$,其中$γ_t(G\Box H)=\frac{1}{2}γ_t(G) γ_t(H)\,$,无论何时$γ_t(H)=2$。此外,我们还得到了一类具有$γ_t(G_n)=2n$的图$G_n$,它们渐近地逼近$γ_t(G_n\Box G_n)\ge \frac{1}{2}γ_t(G_n)^2$中的等式.

英文摘要:

Ho proved in [A note on the total domination number, Util.Math. 77 (2008) 97--100] that the total domination number of the Cartesian product of any two graphs with no isolated vertices is at least one half of the product of their total domination numbers. We extend a result of Lu and Hou from [Total domination in the Cartesian product of a graph and $K_2$ or $C_n$, Util. Math. 83 (2010) 313--322] by characterizing the pairs of graphs $G$ and $H$ for which $γ_t(G\Box H)=\frac{1}{2}γ_t(G) γ_t(H)\,$, whenever $γ_t(H)=2$. In addition, we present an infinite family of graphs $G_n$ with $γ_t(G_n)=2n$, which asymptotically approximate the equality in $γ_t(G_n\Box G_n)\ge \frac{1}{2}γ_t(G_n)^2$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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