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

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A COMPARATIVE STUDY BETWEEN CONVERGENCE RESULTS FOR NEWTON'S METHOD

  • Argyros, Ioannis K.;Hilout, Said
    • The Pure and Applied Mathematics
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    • v.15 no.4
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    • pp.365-375
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    • 2008
  • We present a new theorem for the semilocal convergence of Newton's method to a locally unique solution of an equation in a Banach space setting. Under a gamma-type condition we show that we can extend the applicability of Newton's method given in [12]. We also provide a comparative study between results using the classical Newton-Kantorovich conditions ([6], [7], [10]), and the ones using the gamma-type conditions ([12], [13]). Numerical examples are also provided.

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LOCAL CONVERGENCE RESULTS FOR NEWTON'S METHOD

  • Argyros, Ioannis K.;Hilout, Said
    • Journal of the Chungcheong Mathematical Society
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    • v.25 no.2
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    • pp.267-275
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    • 2012
  • We present new results for the local convergence of Newton's method to a unique solution of an equation in a Banach space setting. Under a flexible gamma-type condition [12], [13], we extend the applicability of Newton's method by enlarging the radius and decreasing the ratio of convergence. The results can compare favorably to other ones using Newton-Kantorovich and Lipschitz conditions [3]-[7], [9]-[13]. Numerical examples are also provided.

CHEYSHEFF-HALLEY-LIKE METHODS IN BANACH SPACES

  • Argyros, Ioannis-K.
    • Journal of applied mathematics & informatics
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    • v.4 no.1
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    • pp.83-108
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    • 1997
  • Chebysheff-Halley methods are probably the best known cubically convergent iterative procedures for solving nonlinear equa-tions. These methods however require an evaluation of the second Frechet-derivative at each step which means a number of function eval-uations proportional to the cube of the dimension of the space. To re-duce the computational cost we replace the second Frechet derivative with a fixed bounded bilinear operator. Using the majorant method and Newton-Kantorovich type hypotheses we provide sufficient condi-tions for the convergence of our method to a locally unique solution of a nonlinear equation in Banach space. Our method is shown to be faster than Newton's method under the same computational cost. Finally we apply our results to solve nonlinear integral equations appearing in radiative transfer in connection with the problem of determination of the angular distribution of the radiant-flux emerging from a plane radiation field.

ON THE SEMI-LOCAL CONVERGENCE OF CONTRAHARMONIC-MEAN NEWTON'S METHOD (CHMN)

  • Argyros, Ioannis K.;Singh, Manoj Kumar
    • Communications of the Korean Mathematical Society
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    • v.37 no.4
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    • pp.1009-1023
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    • 2022
  • The main objective of this work is to investigate the study of the local and semi-local convergence of the contraharmonic-mean Newton's method (CHMN) for solving nonlinear equations in a Banach space. We have performed the semi-local convergence analysis by using generalized conditions. We examine the theoretical results by comparing the CHN method with the Newton's method and other third order methods by Weerakoon et al. using some test functions. The theoretical and numerical results are also supported by the basins of attraction for a selected test function.

SEMILOCAL CONVERGENCE THEOREMS FOR A CERTAIN CLASS OF ITERATIVE PROCEDURES

  • Ioannis K. Argyros
    • Journal of applied mathematics & informatics
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    • v.7 no.1
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    • pp.29-40
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    • 2000
  • We provide semilocal convergence theorems for Newton-like methods in Banach space using outer and generalized inverses. In contrast to earlier results we use hypotheses on the second instead of the first Frechet-derivative. This way our Newton-Kantorovich hypotheses differ from earlier ones. Our results can be used to solve undetermined systems, nonlinear least square problems and ill-posed nonlinear operator equations.

ON THE "TERRA INCOGNITA" FOR THE NEWTON-KANTROVICH METHOD WITH APPLICATIONS

  • Argyros, Ioannis Konstantinos;Cho, Yeol Je;George, Santhosh
    • Journal of the Korean Mathematical Society
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    • v.51 no.2
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    • pp.251-266
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    • 2014
  • In this paper, we use Newton's method to approximate a locally unique solution of an equation in Banach spaces and introduce recurrent functions to provide a weaker semilocal convergence analysis for Newton's method than before [1]-[13], in some interesting cases, provided that the Fr$\acute{e}$chet-derivative of the operator involved is p-H$\ddot{o}$lder continuous (p${\in}$(0, 1]). Numerical examples involving two boundary value problems are also provided.

CONVERGENCE OF THE RELAXED NEWTON'S METHOD

  • Argyros, Ioannis Konstantinos;Gutierrez, Jose Manuel;Magrenan, Angel Alberto;Romero, Natalia
    • Journal of the Korean Mathematical Society
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    • v.51 no.1
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    • pp.137-162
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    • 2014
  • In this work we study the local and semilocal convergence of the relaxed Newton's method, that is Newton's method with a relaxation parameter 0 < ${\lambda}$ < 2. We give a Kantorovich-like theorem that can be applied for operators defined between two Banach spaces. In fact, we obtain the recurrent sequence that majorizes the one given by the method and we characterize its convergence by a result that involves the relaxation parameter ${\lambda}$. We use a new technique that allows us on the one hand to generalize and on the other hand to extend the applicability of the result given initially by Kantorovich for ${\lambda}=1$.

A MESH INDEPENDENCE PRINCIPLE FOR PERTURBED NEWTON-LIKE METHODS AND THEIR DISCRETIZATIONS

  • Argyros, Ioannis K.
    • Journal of applied mathematics & informatics
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    • v.7 no.1
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    • pp.139-159
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    • 2000
  • In this manuscript we study perturbed Newton-like methods for the solution of nonlinear operator equations in a Banach space and their discretized versions in connection with the mesh independence principle. This principle asserts that the behavior of the discretized process is asymptotically the same as that for the original iteration and consequently, the number of steps required by the two processes to converge to within a given tolerance is essentially the same. So far this result has been proved by others using Newton's method for certain classes of boundary value problems and even more generally by considering a Lipschitz uniform discretization. In some of our earlierpapers we extend these results to include Newton-like methods under more general conditions. However, all previous results assume that the iterates can be computed exactly. This is mot true in general. That in why we use perturbed Newton-like methods and even more general conditions. Our results, on the one hand, extend, and on the other hand, make more practical and applicable all previous results.