eprintid: 1056733 rev_number: 50 eprint_status: archive userid: 608 dir: disk0/01/05/67/33 datestamp: 2011-02-14 21:21:23 lastmod: 2021-11-29 00:21:19 status_changed: 2011-02-16 15:05:01 type: article metadata_visibility: show item_issues_count: 0 creators_name: Betcke, T creators_name: Kressner, D title: Perturbation, extraction and refinement of invariant pairs for matrix polynomials ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F59 keywords: Polynomial eigenvalue problem, Invariant pairs, Numerical algorithm, Perturbation theory, QUADRATIC EIGENVALUE PROBLEMS, NUMERICAL-SOLUTION, SUBSPACES, LINEARIZATIONS, ALGORITHM, BOUNDS, ERROR abstract: 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. (C) 2010 Elsevier Inc. All rights reserved. date: 2011-08-01 publisher: ELSEVIER SCIENCE INC official_url: http://dx.doi.org/10.1016/j.laa.2010.06.029 vfaculties: VMPS oa_status: green language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_batch elements_source: Web of Science elements_id: 290116 doi: 10.1016/j.laa.2010.06.029 lyricists_name: Betcke, Timo lyricists_id: TBETC52 full_text_status: public publication: Linear Algebra and its Applications volume: 435 number: 3 pagerange: 514-536 issn: 0024-3795 citation: Betcke, T; Kressner, D; (2011) Perturbation, extraction and refinement of invariant pairs for matrix polynomials. Linear Algebra and its Applications , 435 (3) pp. 514-536. 10.1016/j.laa.2010.06.029 <https://doi.org/10.1016/j.laa.2010.06.029>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1056733/2/BeKr09.pdf