Lecturer: Zhao Yi

Abstract:

In 1975 Bollobás, Erdős, and Szemerédi asked the following question: given positive integers with, what is the largest minimum degree among all-partite graphs with parts of size and which do not contain a copy of ? The case has attracted a lot of attention and was fully resolved by Haxell and Szabó, and Szabó and Tardos in 2006. In this talk we discuss a recent join work with Lo and Treglown on the case of the problem, including an exact solution in the case when. We will also discuss Turán numbers in multipartite graphs, which can be viewed as a generalization of Zarankiewicz problem, including a recent work with Han on the Turán number of disjoint triangles in 4-partite graphs.

Introduction to the Lecturer:

Zhao Yi, a professor at Georgia State University in the United States, graduated from Tsinghua University, China in 1994, studied at Rutgers University in the United States, studied under Professor Endre Szemerédi, an internationally renowned mathematician and winner of the Abel Prize in International Mathematics in 2012, and obtained his doctorate in 2001. From 2002 to 2005, he worked as an assistant professor at the University of Illinois University in the United States, and successively served as an assistant professor, associate professor and professor in the Department of Mathematics of Georgia State University in the United States. Professor Zhao Yi's main research fields include extreme value combination, graph theory and theoretical computer. He has published and accepted many papers in international famous journals such as JCTB, SIAM Discovery Math., JCTA and JGT.

Invitee:

Wang Guanghui, Professor from School of Mathematics

Time:

9:00 on December 24 (Friday)

Venue:

zoom conference, conference number: 861 6162 2824, password: 202121

Hosted by: School of Mathematics, Shandong University