On the cop number and the weak Meyniel conjecture for algebraic graphs

Abstract

We show that the cop number of the Cayley sum graph of a finite group $G$ with respect to a symmetric subset $S$ is at most twice its degree when the graph is connected, undirected. We also prove that a similar bound holds for the cop number of generalised Cayley graphs and twisted Cayley sum graphs under some conditions. These extend a result of Frankl to such graphs. Using the above bounds and a result of Bollob\'{a}s--Janson--Riordan, we show that the weak Meyniel conjecture holds for these algebraic graphs.