A generating pair $x, y$ for a group $G$ is said to be \textbf{ \textit{ symmetric}} if there exists an automorphism $\varphi_{ x,y}$ of $G$ inverting both $x$ and $y$, that is, $x^{ \varphi_{ x,y}}=x^{ -1}$ and $y^{ \varphi_{ x,y}}=y^{ -1}$. Similarly, a group $G$ is said to be \textbf{ \textit{ strongly symmetric}} if $G$ can be generated with two elements and if all generating pairs of $G$ are symmetric. In this paper we classify the finite strongly symmetric non-abelian simple groups. Combinatorially, these are the finite non-abelian simple groups $G$ such that every orientably regular hypermap with monodromy group $G$ is reflexible.
Categories: math.GR math.CO