On the Diameter and Girth of an Annihilating-Ideal Graph

Abstract

Let $R$ be a commutative ring with $1\ne 0$ and $\mathbb{A}(R)$ be the set of ideals with nonzero annihilators. The annihilating-ideal graph of $R$ is defined as the graph $\mathbb{AG}(R)$ with the vertex set $\mathbb{A}(R{)}^{\ast }=\mathbb{A}(R)\setminus \{(0)\}$ and two distinct vertices $I$ and $J$ are adjacent if and only if $IJ=(0)$. In this paper, we first study the interplay between the diameter of annihilating-ideal graphs and zero-divisor graphs. Also, we characterize rings $R$ when $\mathrm{gr}(\mathbb{AG}(R))\ge 4$, and so we characterize rings whose annihilating-ideal graphs are bipartite. Finally, in the last section we discuss on a relation between the Smarandache vertices and diameter of $\mathbb{AG}(R)$.

11 pages, 1 figure