报告题目：A primitivity condition of automorphism groups of flag-transitive 2-designs

报告人：周胜林(华南理工大学)

报告时间：2026年7月7日下午16:30-18:30

报告地点：育才校区广西应用数学中心（广西师范大学）

报告摘要: In this article, we prove that the flag-transitive automorphism group G of a 2-(v,k,\lambda) design \cal D with \lambda\ge \gcd(r,\lambda)^2/3 is point-primitive except for three exceptional cases where G is point-imprimitive. Furthermore, if G\leq Aut({\cal D}) is  point-primitive, then $G$ is of affine, almost simple, or product type with Soc(G)\cong T\times T, where T is a non-abelian simple group and G has rank $3$.  In particular, if \mathcal{D} is symmetric and G is flag-transitive and point-primitive, then it must be of affine or almost simple type. As an application, we proved that if G acts flag-transitively on \cal D with \gcd(r,\lambda)=3, then G is primitive of affine or almost simple except for the 2-(45,12,3) design construct by C.E. Praeger. This is a joint work with Yu Sun.

报告人简介：周胜林，男，博士，教授，博士生导师。1999年于浙江大学获理学博士学位，1999.07-2007.11在汕头大学工作，期间2004.10-2006.10澳大利亚西澳大学公派访问学者。2007年12月至今在华南理工大学数学学院工作。2019.01-2019.02，澳大利亚墨尔本大学高级研究学者。主要从事代数学、有限群论、组合设计等领域的教学和研究工作，已发表SCI论文100余篇，主持国家自然科学基金面上项目4项，省部级项目5项。