Perturbation, extraction and refinement of invariant pairs for matrix polynomials

Betcke, T. and Kressner, D. (2011) Perturbation, extraction and refinement of invariant pairs for matrix polynomials. Linear Algebra and its Applications, 435 (3). pp. 514-536. ISSN 0024-3795 doi: 10.1016/j.laa.2010.06.029

Abstract/Summary

Generalizing the notion of an eigenvector, invariant subspaces are frequently used in the context of linear eigenvalue problems, leading to conceptually elegant and numerically stable formulations in applications that require the computation of several eigenvalues and/or eigenvectors. Similar benefits can be expected for polynomial eigenvalue problems, for which the concept of an invariant subspace needs to be replaced by the concept of an invariant pair. Little has been known so far about numerical aspects of such invariant pairs. The aim of this paper is to fill this gap. The behavior of invariant pairs under perturbations of the matrix polynomial is studied and a first-order perturbation expansion is given. From a computational point of view, we investigate how to best extract invariant pairs from a linearization of the matrix polynomial. Moreover, we describe efficient refinement procedures directly based on the polynomial formulation. Numerical experiments with matrix polynomials from a number of applications demonstrate the effectiveness of our extraction and refinement procedures.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/17674
Identification Number/DOI	10.1016/j.laa.2010.06.029
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Mathematics and Statistics
Publisher	Elsevier
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