On a Perturbation Bound for Invariant Subspaces of Matrices
Michael Karow, Daniel Kreßner · SIAM Journal on Matrix Analysis and Applications · 2014
Given a nonsymmetric matrix $A$, we investigate the effect of perturbations on an invariant subspace of $A$. The result derived in this paper differs from Stewart's classical result and sometimes yields tighter bounds. Moreover, we provide norm estimates for the remainder terms in well-known perturbation expansions for invariant subspaces, eigenvectors, and eigenvalues.