Session B2 - Graph Theory and Combinatorics
July 14, 15:30 ~ 15:55
An application of Hoffman graphs for spectral characterizations of graphs
Maastricht University, The Netherlands - email@example.com
In this paper, we present the first application of Hoffman graphs for spectral characterizations of graphs. In particular, we show that the $2$-clique extension of the $(t+1)\times(t+1)$-grid is determined by its spectrum when $t$ is large enough. This result will help to show that the Grassmann graph $J_2(2D,D)$ is determined by its intersection numbers as a distance regular graph, if $D$ is large enough.
Joint work with Qianqian Yang (University of Science and Technology of China) and Jack H. Koolen (University of Science and Technology of China and Wen-Tsun Wu Key Laboratory of CAS).