{ "id": "1209.2480", "version": "v1", "published": "2012-09-12T02:17:54.000Z", "updated": "2012-09-12T02:17:54.000Z", "title": "Solutions and improved perturbation analysis for the matrix equation X-A^{*}X^{-p}A=Q (p>0)", "authors": [ "Jing Li" ], "comment": "17 pages. arXiv admin note: substantial text overlap with arXiv:1208.3672, arXiv:1208.3518", "categories": [ "math.NA" ], "abstract": "In this paper the nonlinear matrix equation X-A^{*}X^{-p}A=Q with p>0 is investigated. We consider two cases of this equation: the case p>1 and the case 01, a new sufficient condition for the existence of a unique positive definite solution for the matrix equation is obtained. A perturbation estimate for the positive definite solution is derived. Explicit expressions of the condition number for the positive definite solution are given. In the case 0