报告题目：On the Sum of the k Largest Eigenvalues of Adjacency and Laplacian Matrices of Graphs with Applications to Brouwer’s Conjecture
报告人： Kinkar Chandra Das
报告时间：4月12日 9:00-10:00
报告地点：卓越楼810
报告摘要：In this talk, we present some upper bounds on the sum of the k largest eigenvalues of both the adjacency matrix and the Laplacian matrix of graphs. Furthermore, these results are extended to the broader setting of symmetric matrices. When applied to the adjacency matrix of a graph, our bounds improve upon the related results of Mohar [On the sum of k largest eigenvalues of graphs and symmetric matrices, J. Combin. Theory Ser. B 99 (2009) 306–313]. In addition, for the Laplacian matrix, we establish that Brouwer’s well-known conjecture holds for small values of k for almost all graphs, thereby providing a meaningful step toward its complete resolution.
报告人简介：Kinkar Chandra Das 现任韩国成均馆大学（Sungkyunkwan University）教授、博士生导师，是国际公认的图谱理论（Spectral Graph Theory）与离散数学领域专家。其个人学术主页：Kinkar Chandra Das教授主页