Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-12-05T03:04:38.162Z Has data issue: false hasContentIssue false

A two-sided iterative method for computing positive definite solutions of a nonlinear matrix equation

Published online by Cambridge University Press:  17 February 2009

Salah M. El-Sayed
Affiliation:
Department of Mathematics, Faculty of Science, Benha university, Benha 13518, Egypt; e-mail: [email protected].
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In several recent papers, a one-sided iterative process for computing positive definite solutions of the nonlinear matrix equation X + A* X−1A = Q, where Q is positive definite, has been studied. In this paper, a two-sided iterative process for the same equation is investigated. The novel idea here is that the two sequences obtained by starting at two different values provide (a) an interval in which the solution is located, that is, XkXYk for all k and (b) a better stopping criterion. Some properties of solutions are discussed. Sufficient solvability conditions on a matrix A are derived. Moreover, when the matrix A is normal and satisfies an additional condition, the matrix equation has smallest and largest positive definite solutions. Finally, some numerical examples are given to illustrate the effectiveness of the algorithm.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2003

References

[1]Anderson, W. N. Jr., Morley, T. D. and Trapp, G. E., “Positive solution to X = A – BX−1 B*”, Linear Algebra Appl. 134 (1990) 5362.Google Scholar
[2]Buzbee, B. L., Golub, G. H. and Nielson, C. W., “On direct methods for solving Poisson's equations”, SIAM J. Numer. Anal. 7 (1970) 627656.Google Scholar
[3]El-Sayed, S. M., “On the two iteration processes for computing positive definite solutions of equation X – A* X−n A = I”, Comput. Math. Appl. (submitted).Google Scholar
[4]El-Sayed, S. M. and Ran, A. C. M., “On the iteration methods for solving a class of nonlinear matrix equations”, SIAM J. Matrix Anal. Appl. (to appear).Google Scholar
[5]Engwerda, J. C., “On the existence of a positive definite solution of the matrix equation X + AT X−1 A = I”, Linear Algebra Appl. 194 (1993) 91108.Google Scholar
[6]Engwerda, J. C., Ran, A. C. M. and Rijkeboer, A. L., “Necessary and sufficient conditions for the existence of a positive definite solution of the matrix equation X + A* X−1 A = Q”, Linear Algebra Appl. 186 (1993) 255275.CrossRefGoogle Scholar
[7]Guo, C. H. and Lancaster, P., “Iterative solution of two matrix equations”, The Mathematics of Computation 68 (1999) 15891603.Google Scholar
[8]Ivanov, I. G. and El-Sayed, S. M., “Properties of positive definite solutions of the equation X + A* X−2 A = I”, Linear Algebra Appl. 279 (1998) 303316.Google Scholar
[9]Lancaster, P. and Rodman, L., The algebraic Riccati equation (Oxford University Press, Oxford, 1995).CrossRefGoogle Scholar
[10]Than, X., “Computing the extremal positive definite solutions of a matrix equation”, SIAM J. Sci. Comput. 17 (1996) 11671174.Google Scholar
[11]Than, X. and Xie, J., “On the matrix equation X + A* X−1 A = I”, Linear Algebra Appl. 247 (1996) 337345.Google Scholar