西北工业大学李斌龙副教授学术报告

发布日期:2021-11-11    浏览次数:

报告题目Extremal problems of Erdős, Faudree, Schelp and Simonovits on paths and cycles

报告人:李斌龙副教授(西北工业大学)

报告时间:202111171400-1830

报告地点:腾讯会议 992 138 191

 

报告摘要:

For positive integers n>d≥k, let φ(n,d,k) denote the least integer φ such that every n-vertex graph with at least φ vertices of degree at least d contains a path on k+1 vertices. Many years ago, Erdős, Faudree, Schelp and Simonovits proposed the study of the function φ(n,d,k), and conjectured that φ(n,d,k)≤(k-1)/2⌋⌊n/(d+1)+ε, where ε=1 if k is odd and ε=2 otherwise. In this paper we determine the value of the function φ(n,d,k) exactly. This confirms the above conjecture of Erdős et al. for all positive integers k≠4 and in a corrected form for the case k4.

 

报告人简介:

李斌龙,荷兰Twente大学博士,捷克West Bohemia大学博士后,丹麦技术大学访问学者,现为西北工业大学88038威尼斯副教授。主要研究方向为图的Hamilton性及图的Ramsey理论。主持国家自然科学基金青年项目、面上项目各一项。在 JCTB, J. Graph Theory, European J. Combinatorics等期刊发表论文50余篇。