On Cameron's question about primitive permutation groups with stabilizer of two points that is normal in the stabilizer of one of them

A. V. Konygin

Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 19 (2013) no. 3, pp. 187-198

Résumé

Assume that $G$ is a primitive permutation group on a finite set $X$, $x\in X$, $y\in X\setminus\{x\}$, and $G_{x,y}\trianglelefteq G_x$. P. Cameron raised the question about the validity of the equality $G_{x,y}=1$ in this case. The author proved earlier that, if $\mathrm{soc}(G)$ is not a direct power of an exceptional group of Lie type, then $G_{x,y}=1$. In the present paper, we prove that, if $\mathrm{soc}(G)$ is a direct power of an exceptional group of Lie type distinct from $E_6(q)$, $^2E_6(q)$, $E_7(q)$ and $E_8(q)$, then $G_{x,y}=1$.

Détail

Mots-clés : primitive permutation group
Keywords: regular suborbit.