Title: Degree sums and dominating cycles

Keynote Speaker: Chen Yaojun

Abstract:

A cycle C of a graph G is dominating if any vertex of V(G)\V(C) has at least one neighbor on C and V(G)\V(C) is an independent set. Let G be a k-connected graph of order n≥3 with k≥2. In this talk, we will introduce our new result that every longest cycle of G is dominating if the degree sums is more than (k+1)(n+1)/3 for any k+1 pairwise nonadjacent vertices, and the lower bound is sharp, which generalizes the results due to Bondy for k=2 and Lu et al. for k=3.

Introduction to the Speaker:

Chen Yaojun, Professor, Doctoral Supervisor in the Department of Mathematics of Nanjing University, a member of the 9th and 10th Sessions of the Operations Research Society of China. In July 2000, he received his Doctor of Science Degree from the Academy of Mathematics and Systems Science, Chinese Academy of Sciences; From July 2000 to June 2002, he was engaged in post-doctoral research in the School of Mathematics of Nanjing University; From September 2003 to August 2005, he was engaged in post-doctoral research in the Department of Logistics, School of Business of Hong Kong Polytechnic University; At present, he is mainly engaged in the research on the structure of special subgraphs in Graphs, Ramsey number, coding theory, the intersection of theoretical computer and combinatorial graph theory. He has presided over a great many National Natural Science Foundation of China and published many research papers in professional academic journals at home and abroad, of which more than 60 were published in SCI retrieval source journals.

Inviter:

Wang Guanghui Professor in the School of Mathematics

Time:

19:00-20:30 on September 23 (Wednesday)

Location:

Tencent Meeting number: 613 273 088

Sponsored by: School of Mathematics, Shandong University