报告题目:Vertex-primitive $s$-arc-transitive digraphs
报 告 人:夏彬 博士 (西澳大学)
报告时间:2017年01月03日(星期二)上午10:30-11:15
报告地点:4号楼4131室
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数学学院
2017年01月03日
报告摘要:
An $s$-arc in a digraph (directed graph) is a sequence $v_0,v_1,/dots,v_s$ of vertices such that for each admissible $i$, the pair $(v_i,v_{i+1})$ is an arc of the digraph. A digraph $/Gamma$ is said to be $s$-arc-transitive if the automorphism group $/mathrm{Aut}(/Gamma)$ of $/Gamma$ acts transitively on the set of $s$-arcs of $/Gamma$, and is said to be vertex-primitive if $/mathrm{Aut}(/Gamma)$ preserves no nontrivial partition of the vertex set. In this talk I will discuss vertex-primitive $s$-arc-transitive digraphs by different O'Nan-Scott types of vertex-primitive groups, and solve the existence problem of vertex-primitive $2$-arc-transitive digraphs by giving some infinite families. This is joint work with Michael Giudici and Cai Heng Li.
报告人简介:
夏彬博士,2014年毕业于北京大学数学科学学院,2014-2016年在北京国际数学中心从事博士后研究,现为西澳大学Research associate。主要研究方向为置换群与代数组合论。