報 告 人：周進鑫 教授

報告題目：On primitive 2-closed permutation groups of rank at most four 

報告時間：2024年11月15日（周五）下午4：00

報告地點：靜遠樓1508會議室

主辦單位：數學與統計學院、數學研究院、科學技術研究院

報告人簡介：

       周進鑫，北京交通大學數學與統計學院教授，博導，國家自然科學基金杰出青年基金獲得者。主要從事對稱圖論研究。在組合數學、圖論、代數等領域權威期刊Journal of Combinatorial Theory, Series A/B, Combinatorica, European Journal of Combiatorics, Journal of Graph Theory, Journal of Algebra, Journal of Algebraic Combintorics等上發表論文100余篇。主持和參與國家自然科學基金等科研項目10余項。

報告摘要：

       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.