Speaker: Zlatko Drmac, University of Zagreb.

Title: Subspace gap residuals for Rayleigh--Ritz approximations

Abstract:

Large scale eigenvalue and singular value computations are usually based
on extracting information from a compression of the matrix to suitably
chosen low dimensional subspaces. This paper introduces new a posteriori
relative error bounds based on a residual expressed using the largest
principal angle (gap) between relevant subspaces. The eigenvector
approximations are estimated using subspace gaps and relative separation
of the eigenvalues.