报告题目：An improved bound for strongly regular graphs
报告人：Jack Koolen
时间：2026年1月19日 14:30-15:10
地点：四教319
摘要：Sims showed that there are for primitive strongly regular graphs with fixed smallest eigenvalue except for a finite number of them they belong two families of graphs. Later in 1979 Neumaier made this bound explicit. In this talk we will improve this bound by Neumaier. This is based on joint work with Chenhui Lv, Greg Markowsky and Jongyook Park.
报告人简介：
Jack Koolen is currently a full professor at the University of Science and Technology of China. He received his Ph.D. from Eindhoven University of Technology in 1994 under supervision of Prof. Andries Brouwer. After a few postdoc positions in for example Oxford University and Kyushu University, he became an associate professor in POSTECH in Korea. Since 2013 he is a full professor at the University of Science and Technology of China.
His main interest is in algebraic graph theory especially distance-regular graphs. Recently he also got interested in graphs with fixed smallest eigenvalues. He has co-authored a book on phylogenetic combinatorics. He is a managing editor of Graphs and Combinatorics and an associate editor for Designs, Codes and Cryptography. He has published over 100 papers in highly prestigious journals such as Advances in Mathematics, Journal of Combinatorial Theory B, SIAM Journal of Discrete Mathematics, etc.
