Superior properties of the PRESB preconditioner for operators on two-by-two block form with square blocks

0534464 - ÚGN 2021 RIV DE eng J - Journal Article
Axelsson, Owe - Karátson, J.
Superior properties of the PRESB preconditioner for operators on two-by-two block form with square blocks.
Numerische Mathematik. Roč. 146, č. 2 (2020), s. 335-368. ISSN 0029-599X. E-ISSN 0945-3245
R&D Projects: GA MŠMT LQ1602
Institutional support: RVO:68145535
Keywords : preconditioner * PRESB method * superlinear convergence
OECD category: Applied mathematics
Impact factor: 2.223, year: 2020
Method of publishing: Open access
https://link.springer.com/article/10.1007%2Fs00211-020-01143-x

Matrices or operators in two-by-two block form with square blocks arise in numerous important applications, such as in optimal control problems for PDEs. The problems are normally of very large scale so iterative solution methods must be used. Thereby the choice of an efficient and robust preconditioner is of crucial importance. Since some time a very efficient preconditioner, the preconditioned square block, PRESB method has been used by the authors and coauthors in various applications, in particular for optimal control problems for PDEs. It has been shown to have excellent properties,
such as a very fast and robust rate of convergence that outperforms other methods. In this paper the fundamental and most important properties of the method are stressed and presented with new and extended proofs. Under certain conditions, the condition number of the preconditioned matrix is bounded by 2 or even smaller. Furthermore, under certain assumptions the rate of convergence is superlinear.
Permanent Link: http://hdl.handle.net/11104/0312653