Published online by Cambridge University Press: 20 November 2018
Let   $R$  be a commutative ring with non-zero identity. In this paper, we introduce the weakly nilpotent graph of a commutative ring. The weakly nilpotent graph of
 $R$  be a commutative ring with non-zero identity. In this paper, we introduce the weakly nilpotent graph of a commutative ring. The weakly nilpotent graph of   $R$  denoted by
 $R$  denoted by   ${{\Gamma }_{w}}(R)$  is a graph with the vertex set
 ${{\Gamma }_{w}}(R)$  is a graph with the vertex set   ${{R}^{\star }}$  and two vertices
 ${{R}^{\star }}$  and two vertices   $x$  and
 $x$  and   $y$  are adjacent if and only if
 $y$  are adjacent if and only if   $x\,y\in N{{(R)}^{\star }}$ , where
 $x\,y\in N{{(R)}^{\star }}$ , where   ${{R}^{\star }}=R\backslash \{0\}$  and
 ${{R}^{\star }}=R\backslash \{0\}$  and   $N{{(R)}^{\star }}$  is the set of all non-zero nilpotent elements of
 $N{{(R)}^{\star }}$  is the set of all non-zero nilpotent elements of   $R$ . In this article, we determine the diameter of weakly nilpotent graph of an Artinian ring. We prove that if
 $R$ . In this article, we determine the diameter of weakly nilpotent graph of an Artinian ring. We prove that if   ${{\Gamma }_{w}}(R)$  is a forest, then
 ${{\Gamma }_{w}}(R)$  is a forest, then   ${{\Gamma }_{w}}(R)$  is a union of a star and some isolated vertices. We study the clique number, the chromatic number, and the independence number of
 ${{\Gamma }_{w}}(R)$  is a union of a star and some isolated vertices. We study the clique number, the chromatic number, and the independence number of   ${{\Gamma }_{w}}(R)$ . Among other results, we show that for an Artinian ring
 ${{\Gamma }_{w}}(R)$ . Among other results, we show that for an Artinian ring   $R$ ,
 $R$ ,   ${{\Gamma }_{w}}(R)$  is not a disjoint union of cycles or a unicyclic graph. For Artinan rings, we determine diam
 ${{\Gamma }_{w}}(R)$  is not a disjoint union of cycles or a unicyclic graph. For Artinan rings, we determine diam   $\overline{({{\Gamma }_{w}}(R))}$ . Finally, we characterize all commutative rings
 $\overline{({{\Gamma }_{w}}(R))}$ . Finally, we characterize all commutative rings   $R$  for which
 $R$  for which   $\overline{({{\Gamma }_{w}}(R))}$  is a cycle, where
 $\overline{({{\Gamma }_{w}}(R))}$  is a cycle, where   $\overline{({{\Gamma }_{w}}(R))}$  is the complement of the weakly nilpotent graph of
 $\overline{({{\Gamma }_{w}}(R))}$  is the complement of the weakly nilpotent graph of   $R$ .
 $R$ .