全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...
Mathematics  2013 

The intersection graph of ideals of $\mathbb{Z}_n$ is\\ weakly perfect

Full-Text   Cite this paper   Add to My Lib

Abstract:

A graph is called weakly perfect if its vertex chromatic number equals its clique number. Let $R$ be a ring and $I(R)^*$ be the set of all left proper non-trivial ideals of $R$. The intersection graph of ideals of $R$, denoted by $G(R)$, is a graph with the vertex set $I(R)^*$ and two distinct vertices $I$ and $J$ are adjacent if and only if $I\cap J\neq 0$. In this paper, it is shown that $G(\mathbb{Z}_n)$, for every positive integer $n$, is a weakly perfect graph. Also, for some values of $n$, we give an explicit formula for the vertex chromatic number of $G(\mathbb{Z}_n)$. Furthermore, it is proved that the edge chromatic number of $G(\mathbb{Z}_n)$ is equal to the maximum degree of $G(\mathbb{Z}_n)$ unless either $G(\mathbb{Z}_n)$ is a null graph with two vertices or a complete graph of odd order.

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133