设 R是一个任意环,Z(R)是R的中心,R的交换图记为Γ(R),它的顶点集为R\(R),且顶点a和b相连当且仅当它们在R中可交换.该文研究了群环Zn D5的交换图的连通性和直径.主要结果为:若n不等于2或5,那么Γ(Zn D5)是连通的;若Γ(Zn D5)是连通的,则Γ(Zn D5)的直径等于3.
Let R be an arbitrary ring and Z(R) the center of R ,the commuting graph of R ,denotedΓ(R) ,is the graph with the vertex set R/Z(R) ,and two distinct vertices a and b are adjacent if and only if they comute in R .In this paper the connectivity and the diameter of the commuting graph of the group ring ZnD5 are investigated .The main result is that Γ(ZnD5)is connected if n is not equal to 2 or 5 .If Γ(Zn D5 ) is connected ,then diam Γ(Zn D5 )=3 .