Extremal graphs without cycles of lengths i modulo k
主 讲 人 ：李斌龙 教授
活动时间：10月01日08时30分
地 点 ：理科群1号楼D-204
讲座内容：
For integers i and k, an (i mod k)-cycle is one of length i modulo k. Bollobás proved that for every k and i such that kZ+i contains some even numbers (i.e., k is odd or both k, i are even), there is a smallest number ci,k such that every graph of average degree at least ci,k contains an (i mod k)-cycle as a subgraph. Erdős then asked for the exact value of ci,k. In this talk, we present some results for the extremal graphs without (i mod k)-cycle, for k≤4. Joint work with Yandong Bai, Jun Gao, Ervin Győri, Jie Ma, Yufeng Pan, Nika Salia, Casey Tompkins, Kitti Varga, Tianying Xie, Manran Zhu.
主讲人介绍：
李斌龙，西北工业大学教授，博士生导师。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。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、面上项目等项目。在 JCTB, J. Graph Theory, European J. Combinatorics等期刊发表论文60多篇。
