Problem of the Week
BUGCAT
Zassenhaus Conference
Hilton Memorial Lecture
BingAWM
Math Club
Actuarial Association
There has long been an interest in bounds for the eigenvalues of the adjacency matrix of a graph. Recently this has spilled over to the Kirchhoff or Laplacian matrix, and even to signed graphs. I have extended some of these results to graphs with complex unit gains, and have also found new bounds for Laplacian eigenvalues of signed graphs. This talk will be a ramble around some interesting eigenvalue inequalities, old and new.