@article {17675,
title = {A Generalization of Saad{\textquoteright}s Theorem on Rayleigh-Ritz Approximations},
volume = {UMIACS-TR-99-78},
year = {2000},
month = {2000/02/04/},
institution = {Instititue for Advanced Computer Studies, Univ of Maryland, College Park},
abstract = {Let $(\lambda,x)$ be an eigenpair of the Hermitian matrix $A$ of order$n$ and let $(\mu,u)$ be a Ritz pair from a subspace $\clk$ of
$\comp^{2}$. Saad has given a simple inequality bounding
$\sin\angle(x,u)$ in terms of $\sin\angle(x,\clk)$. In this note we
show that this inequality can be extended to an equally simple
inequality for eigenspaces of non-Hermitian matrices.
(Also cross-referenced as UMIACS-TR-99-78)
},
keywords = {Technical Report},
url = {http://drum.lib.umd.edu/handle/1903/1050},
author = {Stewart, G.W.}
}