On extremal problems on k-critical graphs

Abstract

A graph is called k-critical if its chromatic number is k but any proper subgraph has chromatic number less than k. There have been extensive reseach on k-critical graphs over the past decades, yet several basic problems remains widely open. One of such problems is to determine the maximum number of edges in an n-vertex k-critical graph. In this talk, we will discuss some recent results on extremal aspects of k-critical graphs. This is based on some joint works with Jun Gao, Cong Luo and Tianchi Yang.

Speaker Intro

Jie Ma is a professor at the School of Mathematical Sciences of University of Science and Technology of China (USTC). He obtained his Ph.D. degree in 2011 from the School of Mathematics of Georgia Institute of Technology under the supervision of Xingxing Yu. Before joining USTC, he was a Postdoctoral Associate at the Department of Mathematical Sciences of Carnegie Mellon University. Prior to that, he spent two years at the Department of Mathematics of UCLA as a Hedrick Assistant Professor, advised by Benny Sudakov. Jie Ma's primary research interests are in Extremal Combinatorics and Graph Theory. He is currently supported by The National Science Fund for Distinguished Young Scholars of NSFC.