Abstract
The solutions of Hermitian positive-definite Toeplitz systems Anx = b by the preconditioned conjugate gradient method are studied. The preconditioner, called the 'super-optimal' preconditioner, is the circulant matrix Tn that minimizes ∥I - Cn-1 An∥F over all circulant matrices Cn. The convergence rate is known to be governed by the distribution of the eigenvalues of Tn-1 An. For n-by-n Toeplitz matrix An with entries being Fourier coefficients of a positive function in the Wiener class, the asymptotic behaviour of the eigenvalues of the preconditioned matrix Tn-1 An is found as n increases, and it is proved that they are clustered around one.
Original language | English |
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Pages (from-to) | 871-879 |
Number of pages | 9 |
Journal | SIAM Journal on Numerical Analysis |
Volume | 28 |
Issue number | 3 |
DOIs | |
Publication status | Published - Jun 1991 |
Externally published | Yes |
Keywords
- Toeplitz matrix
- super-optimal preconditioner
- circulant matrix
- circulant matrix preconditioned conjugate gradient method