The Turan problems of directed paths and cycles
主 讲 人 :李斌龙 副教授
活动时间:06月25日15时30分
地 点 :理科群1号楼203室
讲座内容:
Let Pk and Ck denote the directed path and thedirected cycle of order k, respectively. In this talk, we determine the maximumsize of Ck-free digraphs of order n for all n,k, as well as the extremaldigraphs. Similar result is obtained for Pk when n is large. In addition, wegeneralize the result of Huang and Lyu [Discrete Math., 2020] by characterizingthe extremal digraphs avoiding an arbitrary orientation of C4.
主讲人介绍:
李斌龙,西北工业大学数学与统计学院副教授,荷兰Twente大学博士,捷克WestBohemia大学博士后,丹麦技术大学访问学者。主要从事图论研究工作,在图的Hamilton性等方面取得一系列研究成果。主持国家自然科学基金青年项目一项。在JCTB, J. Graph Theory, European J. Combinatorics等期刊发表论文50余篇。