Spectral properties of unitary Cayley graphs of finite commutative rings

Xiaogang Liu, Sanming Zhou

Let $R$ be a finite commutative ring. The unitary Cayley graph of $R$, denoted $G_R$, is the graph with vertex set $R$ and edge set $a,b:a,b\in R,a-b\in R^{\times }$, where $R^\t…