Lecture Content：

Erd?s and Simonovits (1973) proposed the following problem: For an integer r≥2 and a family F of non-bipartite graphs, what is the maximum of the minimum degree δ(G) among all n-vertex F-free graphs G with chromatic number at least r? The edge and spectral counterpart of this problem is to determine the maximum size and spectral radius λ(G) among all n-vertex F-free graphs G with chromatic number at least r. In this talk, we will first introduce some relevant background and then present some of our extremal results for C2k+1-free graphs with high chromatic number.

Speaker Introduction:

Lantao Zou received his Ph.D. from Hunan University, advised by Professor Yuejian Peng. His main research interest is extremal graph theory. Currently, he has published several papers in journals such as Journal of Graph Theory and Discrete Mathematics.