On the average order of a finite group

Abstract

Let $o(G)$ be the average order of a finite group $G$. We show that if $o(G)<c$, where $c\in \{\frac{13}{6},\frac{11}{4}\}$, then $G$ is an elementary abelian 2-group or a solvable group, respectively. Also, we prove that the set containing the average orders of all finite groups is not dense in $[a,\infty )$, for all $a\in [0,\frac{13}{6}]$. We also outline some results related to the integer values of the average order. Since group element orders is a popular research topic, we pose some open problems concerning the average order of a finite group throughout the paper.

accepted for publication; 12 pages