Lecturer: Chen Yaojun

Abstract:

LetG₁,G₂, …,G_kbekgiven graphs. The Ramsey numberR(G₁,G₂,…,G_k) is the smallest integerNsuch that for anyk-edge colorings of a complete graphK_N,K_Ncontains a subgraph in coloriwhich is isomorphic toG_ifor some 1≤i≤k.In this talk, we will introduce some results and problems on the Ramsey numbers concerning quadrilaterals, that is, a cycle of length four. We will also talk about the main methods used to investigate these problems.

Introduction to the Lecturer:

Chen Yaojun is a professor and doctoral supervisor from the Department of Mathematics, Nanjing University. In July 2000, he obtained a degree of doctor of science from the Academy of Mathematics and Systems Science,Chinese Academy of Sciences. From July 2000 to June 2002, he was engaged in the postdoctoral research in the Department of Mathematics, Nanjing University. From September 2003 to August 2005, he was engaged in the postdoctoral research in the Department of Logistics, Faculty of Business, Hong Kong Polytechnic University. At present, he is mainly engaged in the research of specific subgraph structure, Ramsey number, coding theory, theoretical computer and combinatorics and graph theory. He has successively presided over a number of programs of National Natural Science Foundation of China and issued more than 70 research papers in professional academic journals at home and abroad.

Invitee:

Yan Jin, Professor from School of Mathematics

Time:

20:00, December 6 (Monday)

Venue:

Zoom account: 86022696421, password: 332863

Hosted by the School of Mathematics, Shandong University