Please use this identifier to cite or link to this item:
Title: Abstract perturbed Krylov methods
Language: English
Authors: Zemke, Jens-Peter M. 
Keywords: Abstract perturbed Krylov method;inexact Krylov method;finite precision;Hessenberg matrix;basis polynomial
Issue Date: Jul-2005
Part of Series: Preprints des Institutes für Mathematik 
Volume number: 89
Abstract (english): We introduce the framework of abstract perturbed Krylov methods''. This is a new and unifying point of view on Krylov subspace methods based solely on the matrix equation $AQ_k+F_k=Q_{k+1}underline{C}_k=Q_kC_k+q_{k+1}c_{k+1,k}e_k^T$ and the assumption that the matrix $C_k$ is unreduced Hessenberg. We give polynomial expressions relating the Ritz vectors, (Q)OR iterates and (Q)MR iterates to the starting vector $q_1$ and the perturbation terms ${f_l}_{l=1}^k$. The properties of these polynomials and similarities between them are analyzed in some detail. The results suggest the interpretation of abstract perturbed Krylov methods as additive overlay of several abstract exact Krylov methods.
DOI: 10.15480/882.100
Institute: Mathematik E-10 
Type: Preprint (Vorabdruck)
Appears in Collections:Publications (tub.dok)

Files in This Item:
File Description SizeFormat
rep89.pdf388,7 kBAdobe PDFThumbnail
Show full item record

Page view(s)

Last Week
Last month
checked on May 20, 2019


checked on May 20, 2019

Google ScholarTM



Items in TORE are protected by copyright, with all rights reserved, unless otherwise indicated.