Abstract
A polynomial preconditioner to an invertible matrix is constructed from the (near) best uniform polynomial approximation to the function 1/x on the eigenvalues of the matrix. The preconditioner is developed using symmetric matrices whose eigenvalues are located in the union of two (disjoint) intervals. The full spectrum of the matrix need not be known in order for the strategy to be applicable. All that is essential is an estimate on the bounds of the larger of the two clusters of eigenvalues. The algorithm, based on the strategy, is shown to be numerically stable with respect to the size of the matrix. In fact it yields, at low cost, an approximation to the inverse of the matrix to within a specified tolerance.
Original language | English |
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Pages (from-to) | 757-769 |
Number of pages | 13 |
Journal | Complex Variables and Elliptic Equations |
Volume | 52 |
Issue number | 9 |
DOIs | |
State | Published - 2007 |
Externally published | Yes |
Funding
The authors wish to express their appreciation to James Hyman and Rob Indik for very fruitful discussions. JMR is supported by a DOE ‘Early Career’ grant DE-FG02-02ER25533. JMR also thanks T7 at Los Alamos, where much of this work was performed. MH was supported by a NSF/VIGRE fellowship.
Funders | Funder number |
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VIGRE | |
National Science Foundation | |
U.S. Department of Energy | DE-FG02-02ER25533 |
Keywords
- 41A05
- 41A25
- 41A28
- 65F10
- 65F15
- AMS Subject Classifications
- Matrix preconditioning
- Normal matrices
- Polynomial approximation