On primitive $2$-closed permutation groups of rank at most four

发布时间：2022-06-07 作者：浏览次数：

Speaker:	周进鑫	DateTime:	2022年6月9日（周四）上午9:00-10:00
Brief Introduction to Speaker: 周进鑫，北京交通大学教授。		Place:	腾讯会议
Abstract:In this talk, I will discuss the characterisation of the primitive 2-closed groups $G$ of rank at most four that are not the automorphism group of a graph or digraph, and we show that if the degree is at least 2402 then there are just two infinite families or $G\leq {\rm A\Gamma L}_1(p^d)$, the 1-dimensional affine semilinear group. To the best of our knowledge, these are the first known examples of non-regular 2-closed groups that are not the automorphism group of a graph or digraph. This is a joint work with Michael Giudici and Luke Morgan.