報 告 人：周進(jìn)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(yuǎn)樓1508會議室

主辦單位：數(shù)學(xué)與統(tǒng)計學(xué)院、數(shù)學(xué)研究院、科學(xué)技術(shù)研究院

報告人簡介：

       周進(jìn)鑫，北京交通大學(xué)數(shù)學(xué)與統(tǒng)計學(xué)院教授，博導(dǎo)，國家自然科學(xué)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(shù)學(xué)、圖論、代數(shù)等領(lǐng)域權(quán)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(fā)表論文100余篇。主持和參與國家自然科學(xué)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.