• Title/Summary/Keyword: Newton's method, Banach space

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ON THE APPLICABILITY OF TWO NEWTON METHODS FOR SOLVING EQUATIONS IN BANACH SPACE

  • Argyros, Ioannis K.
    • Journal of applied mathematics & informatics
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    • v.6 no.2
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    • pp.369-378
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    • 1999
  • In This study we examine the applicability of Newton's method and the modified Newton's method for a, pp.oximating a lo-cally unique solution of a nonlinear equation in a Banach space. We assume that the newton-Kantorovich hypothesis for Newton's method is violated but the corresponding condition for the modified Newton method holds. Under these conditions there is no guaran-tee that Newton's method starting from the same initial guess as the modified Newton's method converges. Hence it seems that we must always use the modified Newton method under these condi-tions. However we provide a numerical example to demonstrate that in practice this may not be a good decision.

CONVERGENCE OF THE NEWTON METHOD FOR AUBIN CONTINUOUS MAPS

  • Argyros, Ioannis K.
    • East Asian mathematical journal
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    • v.25 no.2
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    • pp.153-157
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    • 2009
  • Motivated by optimization considerations we revisit the work by Dontchev in [7] involving the convergence of Newton's method to a solution of a generalized equation in a Banach space setting. Using the same hypotheses and under the same computational cost we provide a finer convergence analysis for Newton's method by using more precise estimates.

ON THE RADIUS OF CONVERGENCE OF SOME NEWTON-TYPE METHODS IN BANACH SPACES

  • Argyros, Ioannis K.;Hilout, Said
    • The Pure and Applied Mathematics
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    • v.18 no.3
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    • pp.219-230
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    • 2011
  • We determine the radius of convergence for some Newton{type methods (NTM) for approximating a locally unique solution of an equation in a Banach space setting. A comparison is given between the radii of (NTM) and Newton's method (NM). Numerical examples further validating the theoretical results are also provided in this study.

LOCAL CONVERGENCE OF NEWTON'S METHOD FOR PERTURBED GENERALIZED EQUATIONS

  • Argyros Ioannis K.
    • The Pure and Applied Mathematics
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    • v.13 no.4 s.34
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    • pp.261-267
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    • 2006
  • A local convergence analysis of Newton's method for perturbed generalized equations is provided in a Banach space setting. Using center Lipschitzian conditions which are actually needed instead of Lipschitzian hypotheses on the $Fr\'{e}chet$-derivative of the operator involved and more precise estimates under less computational cost we provide a finer convergence analysis of Newton's method than before [5]-[7].

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IMPROVED CONVERGENCE RESULTS FOR GENERALIZED EQUATIONS

  • Argyros, Ioannis K.
    • East Asian mathematical journal
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    • v.24 no.2
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    • pp.161-168
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    • 2008
  • We revisit the study of finding solutions of equations containing a differentiable and a continuous term on a Banach space setting [1]-[5], [9]-[11]. Using more precise majorizing sequences than before [9]-[11], we provide a semilocal convergence analysis for the generalized Newton's method as well the generalized modified Newton's method. It turns out that under the same or even weaker hypotheses: finer error estimates on the distances involved, and an at least as precise information on the location of the solution can be obtained. The above benefits are obtained under the same computational cost.

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CONVERGENCE THEOREMS FOR NEWTON'S AND MODIFIED NEWTON'S METHODS

  • Argyros, Ioannis K.
    • The Pure and Applied Mathematics
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    • v.16 no.4
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    • pp.405-416
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    • 2009
  • In this study we are concerned with the problem of approximating a locally unique solution of an equation in a Banach space setting using Newton's and modified Newton's methods. We provide weaker convergence conditions for both methods than before [5]-[7]. Then, we combine Newton's with the modified Newton's method to approximate locally unique solutions of operator equations. Finer error estimates, a larger convergence domain, and a more precise information on the location of the solution are obtained under the same or weaker hypotheses than before [5]-[7]. The results obtained here improve our earlier ones reported in [4]. Numerical examples are also provided.

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CONCERNING THE RADIUS OF CONVERGENCE OF NEWTON'S METHOD AND APPLICATIONS

  • Argyros, Ioannis K.
    • Journal of applied mathematics & informatics
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    • v.6 no.3
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    • pp.685-696
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    • 1999
  • We present local and semilocal convergence results for New-ton's method in a Banach space setting. In particular using Lipschitz-type assumptions on the second Frechet-derivative we find results con-cerning the radius of convergence of Newton's method. Such results are useful in the context of predictor-corrector continuation procedures. Finally we provide numerical examples to show that our results can ap-ply where earlier ones using Lipschitz assumption on the first Frechet-derivative fail.

ON THE CONVERGENCE OF NEWTON'S METHOD AND LOCALLY HOLDERIAN INVERSES OF OPERATORS

  • Argyros, Ioannis K.
    • The Pure and Applied Mathematics
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    • v.16 no.1
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    • pp.13-18
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    • 2009
  • A semilocal convergence analysis is provided for Newton's method in a Banach space. The inverses of the operators involved are only locally $H{\ddot{o}}lderian$. We make use of a point-based approximation and center-$H{\ddot{o}}lderian$ hypotheses for the inverses of the operators involved. Such an approach can be used to approximate solutions of equations involving nonsmooth operators.

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ON THE SOLUTION OF NONLINEAR EQUATIONS CONTAINING A NON-DIFFERENTIABLE TERM

  • Argyros, Ioannis K.
    • East Asian mathematical journal
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    • v.24 no.3
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    • pp.295-304
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    • 2008
  • We approximate a locally unique solution of a nonlinear operator equation containing a non-differentiable operator in a Banach space setting using Newton's method. Sufficient conditions for the semilocal convergence of Newton's method in this case have been given by several authors using mainly increasing sequences [1]-[6]. Here, we use center as well as Lipschitz conditions and decreasing majorizing sequences to obtain new sufficient convergence conditions weaker than before in many interesting cases. Numerical examples where our results apply to solve equations but earlier ones cannot [2], [5], [6] are also provided in this study.

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ON THE CONVERGENCE OF NEWTON'S METHOD AND LOCALLY $H{\ddot{O}}LDERIAN$ OPERATORS

  • Argyros, Ioannis K.
    • The Pure and Applied Mathematics
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    • v.15 no.2
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    • pp.111-120
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    • 2008
  • A semi local convergence analysis is provided for Newton's method in a Banach space setting. The operators involved are only locally Holderian. We make use of a point-based approximation and center-Holderian hypotheses. This approach can be used to approximate solutions of equations involving nonsmooth operators.

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