English

On the intersection graph of ideals of $\mathbb{Z}_m$

Commutative Algebra 2017-03-06 v1 Combinatorics

Abstract

Let m>1m>1 be an integer, and let I(Zm)I(\mathbb{Z}_m)^* be the set of all non-zero proper ideals of Zm\mathbb{Z}_m. The intersection graph of ideals of Zm\mathbb{Z}_m, denoted by G(Zm)G(\mathbb{Z}_m), is a graph with vertices I(Zm)I(\mathbb{Z}_m)^* and two distinct vertices I,JI(Zm)I,J\in I(\mathbb{Z}_m)^* are adjacent if and only if IJ0I\cap J\neq 0. Let n>1n>1 be an integer and Zn\mathbb{Z}_n be a Zm\mathbb{Z}_m-module. In this paper, we introduce and study a kind of graph structure of Zm\mathbb{Z}_m, denoted by Gn(Zm)G_n(\mathbb{Z}_m). It is the undirected graph with the vertex set I(Zm)I(\mathbb{Z}_m)^*, and two distinct vertices II and JJ are adjacent if and only if IZnJZn0I\mathbb{Z}_n\cap J\mathbb{Z}_n\neq 0. Clearly, Gm(Zm)=G(Zm)G_m(\mathbb{Z}_m)=G(\mathbb{Z}_m). We obtain some graph theoretical properties of Gn(Zm)G_n(\mathbb{Z}_m) and we compute some of its numerical invariants, namely girth, independence number, domination number, maximum degree and chromatic index. We also determine all integer numbers nn and mm for which Gn(Zm)G_n(\mathbb{Z}_m) is Eulerian.

Keywords

Cite

@article{arxiv.1703.01150,
  title  = {On the intersection graph of ideals of $\mathbb{Z}_m$},
  author = {Soheila Khojasteh},
  journal= {arXiv preprint arXiv:1703.01150},
  year   = {2017}
}