{"title":"Exact Formula for Solving a Degenerate System of Quadratic Equations","authors":"Yu. G. Evtushenko, A. A. Tret’yakov","doi":"10.1134/s0965542524030072","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper is devoted to the solution of a nonlinear system of equations <span>\\(F(x{{) = 0}_{n}}\\)</span>, where <span>\\(F\\)</span> is a quadratic mapping acting from <span>\\({{\\mathbb{R}}^{n}}\\)</span> to <span>\\({{\\mathbb{R}}^{n}}\\)</span>. The derivative <span>\\(F{\\kern 1pt} '\\)</span> is assumed to be degenerate at the solution point, which is a major characteristic property of nonlinearity of the mapping. Based on constructions of the <i>p</i>-regularity theory, a 2-factor method is proposed for solving the system of equations, which converges at a quadratic rate. Moreover, an exact formula is obtained for solving this quadratic system of equations in the case of a 2-regular mapping <span>\\(F(x)\\)</span>.</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1134/s0965542524030072","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The paper is devoted to the solution of a nonlinear system of equations \(F(x{{) = 0}_{n}}\), where \(F\) is a quadratic mapping acting from \({{\mathbb{R}}^{n}}\) to \({{\mathbb{R}}^{n}}\). The derivative \(F{\kern 1pt} '\) is assumed to be degenerate at the solution point, which is a major characteristic property of nonlinearity of the mapping. Based on constructions of the p-regularity theory, a 2-factor method is proposed for solving the system of equations, which converges at a quadratic rate. Moreover, an exact formula is obtained for solving this quadratic system of equations in the case of a 2-regular mapping \(F(x)\).