Bounds on sums of graph eigenvalues

Series: 
Math Physics Seminar
Friday, February 1, 2013 - 16:00
1 hour (actually 50 minutes)
Location: 
Skiles 006
,  
Georgia Tech
,  
I'll discuss two methods for finding bounds on sums of graph eigenvalues (variously for the Laplacian, the renormalized Laplacian, or the adjacency matrix). One of these relies on a Chebyshev-type estimate of the statistics of a subsample of an ordered sequence, and the other is an adaptation of a variational argument used by P. Kröger for Neumann Laplacians.  Some of the inequalities are sharp in suitable senses.  This is ongoing work with J. Stubbe of EPFL