The zero-divisor graph of a ring with involution
Abstract
For a *-ring A, we associate a simple undirected graph Γ*(A) having all nonzero left zero-divisors of A as vertices and, two vertices x and y are adjacent if xy*=0. In case of Artinian *-rings and Rickart *-rings, characterizations are obtained for those *-rings having Γ*(A) a complete graph or a star graph, and sufficient conditions are obtained for Γ*(A) to be connected and also for Γ*(A) to be disconnected. For a Rickart *-ring A, we characterize the girth of gr(Γ*(A)) and prove a sort of Beck’s conjecture.
Communicated by P. Ara