一、讲座主题

On the Seymour's second neighbourhood conjecture

二、时间

9月25日（周三）10:30

三、地点

中心校区知新楼B座924报告厅

四、主讲人

李瑞娟

五、主讲人简介

李瑞娟，山西大学副教授，毕业于德国亚琛工业大学，山西省优秀青年学术带头人，山西省“三晋英才”支持计划青年优秀人才。主要从事图论领域中的结构图论、有向图等方向的理论研究，多次主持国家自然科学基金和省部级的项目，在Journal of Graph Theory, Discrete Mathematics，Discrete Applied Mathematics, Graphs and Combinatorics等学术期刊上发表论文40余篇。

六、摘要

One of the most interesting and challenging open questions concerning digraphs is Seymour's Second Neighbourhood Conjectur (SSNC), which asserts that one can always find, in an oriented graph D, a vertex x whose second out-neighbourhood is at least as large as its out-neighbourhood. As we know SSNC is the special case of Caccetta-Häggkvist conjecture when both in- and out-degrees are at least n/3. In this talk, we introduce the current research status and progress as well as the approaches and technique surrounding this conjecture.

七、邀请人

颜谨 数学学院教授

八、主办

山东大学数学学院