Groups all of whose undirected Cayley graphs are integral

Alireza Abdollahi, Mojtaba Jazaeri

Let $G$ be a finite group, $S\subseteq G\setminus \{1\}$ be a set such that if $a\in S$, then $a^{-1}\in S$, where $1$ denotes the identity element of $G$. The undirected Cayley gra…