Schur Complement Reduction in the Mixed-Hybrid Approximation of Darcy's Law: Rounding Error Analysis

0403487 - UIVT-O 20000010 RIV NL eng J - Journal Article
Maryška, Jiří - Rozložník, Miroslav - Tůma, Miroslav
Schur Complement Reduction in the Mixed-Hybrid Approximation of Darcy's Law: Rounding Error Analysis.
Journal of Computational and Applied Mathematics. Roč. 117, - (2000), s. 159-173. ISSN 0377-0427. E-ISSN 1879-1778
R&D Projects: GA AV ČR IAA2030706; GA ČR GA201/98/P108
Institutional research plan: AV0Z1030915
Keywords : potential fluid flow problem * symmetric indefinite linear systems * Schur complement reduction * iterative methods * rounding error analysis
Subject RIV: BA - General Mathematics
Impact factor: 0.455, year: 2000

Block LU factorization can be unstable even when the system matrix is symetric positive definite. Examination of this type of conditional stability for a particular application in the underground water flow modeling. Actual error of the computed approximate solution depends not only on the user-defined tolerance in the conjugate gradient process but also on the spectra properties of the corresponding matrix blocks eliminated during the Schur complement reduction.
Permanent Link: http://hdl.handle.net/11104/0123791