Ramanujan Cayley Graphs with Normal Connection Sets in Ratio-One Frobenius Groups

Ming-Hsuan Kang, Chi-Jung Yang

Let $G=N⋊H$ be a finite Frobenius group with $|N|=q$ and $|H|=q-1$. We classify all Ramanujan Cayley graphs of $G$ whose connection sets are normal, in the sense of being un…