2 papers
math.CO2026
Upper bounds of the second largest eigenvalue of graphs
Zhiwen Wang, Zihao Geng, Ji-Ming Guo
Let denote the -th largest eigenvalue of adjacency matrix of a graph . Gerschgorin's Theorem indicates belongs to the largest disk, i.e., $λ_1(G)\leÎ_1(…
math.CO2026
Extremal results on the second largest eigenvalue of graphs with given order
Zhiwen Wang, Ji-Ming Guo
In this paper, we demonstrate the effects on the second largest eigenvalue of a connected graph after edge addition or deletion. In 1989, Chung, Graham and Wilson sho…