Search

In this article, we consider two parametric classes of derivative free iterative methods of high order of convergence in Banach spaces. We study local and semilocal convergence results in Banach spaces for both families of iterative processes. We carry out a numerical application to solve a nonlinear and nondifferentiable Fredholm integral equation in the Banach space of continuous functions with the maximum norm. [ABSTRACT FROM AUTHOR]

In this paper, we study the simplest quadratic matrix equation: Q(X)=X2+BX+C=0$$ \mathcal{Q}(X)={X}^2+ BX+C=0 $$. We transform this equation into an equivalent fixed‐point equation, and based on it, we construct the Krasnoselskij method. From this transformation, we can obtain iterative schemes more accurate than the successive approximation method. Moreover, under suitable conditions, we establish different results for the existence and localization of a solution for this equation with the Krasnoselskij method. Finally, we see numerically that the predictor–corrector iterative scheme, with the Krasnoselskij method as a predictor and the Newton method as corrector method, can improve the numerical application of the Newton method when approximating a solution of the quadratic matrix equation. [ABSTRACT FROM AUTHOR]

In this paper, we have studied local convergence of Super-Halley method in Banach spaces under the assumption of second order majorant conditions. This approach allows us to obtain generalization of earlier convergence analysis under majorizing sequences. Two important special cases of the convergence analysis based on the premises of Kantorovich and Smale type conditions have also been concluded. To show efficacy of our approach we have given three numerical examples.

This paper is devoted to convergence study and analysis of a fifthorder iterative method to solve nonlinear equations in Banach spaces. The idea of the Lipschitz condition on the second Fréchet derivative has been used to obtain semilocal convergence balls, R-order of convergence and error bounds by following the main theorem. The local convergence follows under weak-Lipschitz-type conditions. Theoretical results are verified through numerical examples, including integral equation and boundary value problem. It is observed that better results have been obtained in terms of accuracy and number of iterations in comparison with the well-known existing algorithms using similar information. The basins of attraction of the presented method show good performance as compared to already established methods which enhance the applicability of our approach. [ABSTRACT FROM AUTHOR]

In this paper we have provided sufficient conditions to study semilocal and local convergence of the Stirling’s method. The method is used to find fixed points of nonlinear operator equation. We assume Lipschtiz continuity type conditions on the first Fréchet derivative of the operator but no contractive conditions as in earlier works. This way expand the applicability of this method. Here we introduce a new type of majorizing sequences instead of usual majorizing sequences and recurrence relations. Finally the paper will be concluded with numerical examples and a favorable comparison with known results.

Weierstrass (Sitzungsber Königl Preuss Akad Wiss Berlin II:1085–1101, 1891) introduced his famous iterative method for numerical finding all zeros of a polynomial simultaneously. Kyurkchiev and Ivanov (Ann Univ Sofia Fac Math Mech 78:132–136, 1984) constructed a family of multi-point root-finding methods which are based on the Weierstrass method. The purpose of this research is threefold: (1) to develop a new simple approach for the study of the local convergence of the multi-point simultaneous iterative methods; (2) to present a new local convergence result for this family which improves in several directions the result of Kyurkchiev and Ivanov; (3) to provide semilocal convergence results for Kyurkchiev–Ivanov's family of iterative methods. [ABSTRACT FROM AUTHOR]

In this paper, we construct and study a new family of multi-point Ehrlich-type iterative methods for approximating all the zeros of a uni-variate polynomial simultaneously. The first member of this family is the two-point Ehrlich-type iterative method introduced and studied by Trićković and Petković in 1999. The main purpose of the paper is to provide local and semilocal convergence analysis of the multi-point Ehrlich-type methods. Our local convergence theorem is obtained by an approach that was introduced by the authors in 2020. Two numerical examples are presented to show the applicability of our semilocal convergence theorem.

Abstract In 1991, T. Sakurai, T. Torii and H. Sugiura presented a fourth-order iterative algorithm for finding all zeros of a polynomial simultaneously. In this paper, we provide a detailed convergence analysis (local and semilocal) of this method. The new results improve and complement existing results due to Petković et al. (2003) and Petković (2008). Numerical examples are given to show the applicability of our semilocal convergence results. [ABSTRACT FROM AUTHOR]

In this paper we study the semi-local convergence of the Inverse Weierstrass iterative method for simultaneous approximation of polynomial zeros. We present a semi-local convergence theorem with computationally verifiable initial conditions. Several numerical examples are provided to show the practical applications of the presented theoretical results. [ABSTRACT FROM AUTHOR]

Abstract We have very few literature on fixed point iterative methods for solving nonlinear equations. We consider the Stirling method given by Rall (1969). Based on Stirling method, in this paper, we propose a third order Stirling-like method for finding fixed point for nonlinear equations in Banach spaces. We study the local and semilocal convergence of this method for finding the fixed points of nonlinear equations in Banach spaces. The convergence is established under the assumption that the first order Fréchet derivative satisfies the Lipschitz continuity condition. The existence and uniqueness theorem that establishes the convergence balls of these methods is obtained. We consider the numerical examples for local and semilocal convergence case and calculate the existence and uniqueness region of convergence balls even if we fail to apply the results in Rall (1975), Argyros (1995) and Parhi and Gupta (2010)[11,12] due to the F is not contraction on Ω. [ABSTRACT FROM AUTHOR]

In this paper, we are concerned with the problem of approximating a solution of a nonlinear equations by means of using the Secant method. We present a new semilocal convergence analysis for Secant method using restricted convergence domains. According to this idea we find a more precise domain where the inverses of the operators involved exist than in earlier studies. This way we obtain smaller Lipschitz constants leading to more precise majorizing sequences. Our convergence criteria are weaker and the error bounds are more precise than in earlier studies. Under the same computational cost on the parameters involved our analysis includes the computation of the bounds on the limit points of the majorizing sequences involved. Different real-world applications are also presented to illustrate the theoretical results obtained in this study. [ABSTRACT FROM AUTHOR]

In 1977, Nourein (Intern. J. Comput. Math. 6:3, 1977) constructed a fourth-order iterative method for finding all zeros of a polynomial simultaneously. This method is also known as Ehrlich’s method with Newton’s correction because it is obtained by combining Ehrlich’s method (Commun. ACM 10:2, 1967) and the classical Newton’s method. The paper provides a detailed local convergence analysis of a well-known but not well-studied generalization of Nourein’s method for simultaneous finding of multiple polynomial zeros. As a consequence, we obtain two types of local convergence theorems as well as semilocal convergence theorems (with verifiable initial condition and a posteriori error bound) for the classical Nourein’s method. Each of the new semilocal convergence results improves the result of Petković, Petković and Rančić (J. Comput. Appl. Math. 205:1, 2007) in several directions. The paper ends with several examples that show the applicability of our semilocal convergence theorems.

The convergence analysis both local under weaker Argyros-type conditions and semilocal under ω -condition is established using first order Fréchet derivative for an iteration of fifth order in Banach spaces. This avoids derivatives of higher orders which are either difficult to compute or do not exist at times. The Lipchitz and the Hölder conditions are particular cases of the ω -condition. Examples can be constructed for which the Lipchitz and Hölder conditions fail but the ω -condition holds. Recurrence relations are used for the semilocal convergence analysis. Existence and uniqueness theorems and the error bounds for the solution are provided. Different examples are solved and convergence balls for each of them are obtained. These examples include Hammerstein-type integrals to demonstrate the applicability of our approach. [ABSTRACT FROM AUTHOR]

We present a new semilocal convergence analysis for Secant methods in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. Our analysis includes the computation of the bounds on the limit points of the majorizing sequences involved. Under the same computational cost on the parameters involved our convergence criteria are weaker and the error bounds more precise than in earlier studies. A numerical example is also presented to illustrate the theoretical results obtained in this study. [ABSTRACT FROM AUTHOR]

The aim of this paper is to find new iterative Newton-like schemes inspired by the modified Newton iterative algorithm and prove that these iterations are faster than the existing ones in the literature. We further investigate their behavior and finally illustrate the results by numerical examples. [ABSTRACT FROM AUTHOR]

In this paper, we establish a general theorem for iteration functions in a cone normed space over $${{\mathbb {R}}}^n$$ . Using this theorem together with a general convergence theorem of Proinov (J Complex 33:118-144, 2016), we obtain a local convergence theorem with a priori and a posteriori error estimates as well as a theorem under computationally verifiable initial conditions for the Schröder's iterative method considered as a method for simultaneous computation of polynomial zeros of unknown multiplicity. Numerical examples which demonstrate the convergence properties of the proposed method are also provided. [ABSTRACT FROM AUTHOR]

This paper presents a Q-superquadratically convergent version of Newton's method for solving operator equations in Banach spaces that requires only one operator value and one inverse of the Fréchet derivative per iteration. The R-order of convergence is at least 1+√2. Both a semilocal and a local analysis of the new method are given. The semilocal analysis is done along the lines of the Newton-Kantorovich theorem and provides sufficient conditions for the existence of a solution and the convergence of the iterates. The Q-superquadratic convergence is obtained by assuming that the second Fréchet derivative is Lipschitz continuous. The local analysis assumes that a solution exists and shows that the method converges from any starting point belonging to an explicitly defined neighborhood of the solution called the ball of attraction. To our knowledge this is the first superquadratically convergent method that requires about the same work per iteration as Newton's method. [ABSTRACT FROM AUTHOR]

In 1984, Wang and Zheng (J. Comput. Math. 1984, 1, 70−76) introduced a new fourth order iterative method for the simultaneous computation of all zeros of a polynomial. In this paper, we present new local and semilocal convergence theorems with error estimates for Wang−Zheng’s method. Our results improve the earlier ones due to Wang and Wu (Computing 1987, 38, 75−87) and Petković, Petković, and Rančić (J. Comput. Appl. Math. 2007, 205, 32−52).

In 2011, Petković, Rančić and Milošević (Petković et al., 2011) introduced and studied a new fourth-order iterative method for finding all zeros of a polynomial simultaneously. They obtained a semilocal convergence theorem for their method with computationally verifiable initial conditions, which is of practical importance. In this paper, we provide new local as well as semilocal convergence results for this method over an algebraically closed normed field. Our semilocal results improve and complement the result of Petković, Rančić and Milošević in several directions. The main advantage of the new semilocal results are: weaker sufficient convergence conditions, computationally verifiable a posteriori error estimates, and computationally verifiable sufficient conditions for all zeros of a polynomial to be simple. Furthermore, several numerical examples are provided to show some practical applications of our semilocal results. [ABSTRACT FROM AUTHOR]

We present a new semilocal convergence analysis for Newton-like methods using restricted convergence domains in a Banach space setting. The main goal of this study is to expand the applicability of these methods in cases not covered in earlier studies. The advantages of our approach include, under the same computational cost as previous studies, a more precise convergence analysis under the same computational cost on the Lipschitz constants involved. Numerical studies including a chemical application are also provided in this study. [ABSTRACT FROM AUTHOR]

We present a semilocal as well as a local convergence analysis of Steffensen's method in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. The novelty of this paper is twofold. On the one hand, we show convergence under general conditions including earlier ones as special cases. In particular, these conditions allow the important study when the operator involved is not differentiable. On the other hand, we use a combination of conditions that allow a more precise computation of the upper bounds on the norms of the inverses involved leading to a tighter convergence analysis. Finally, we provide numerical examples involving nonlinear integral equations on mixed Hammerstein type that appear in chemistry, vehicular traffic theory, biology, and queuing theory. [ABSTRACT FROM AUTHOR]

We present a semilocal and local convergence analysis of Newton's method on a Banach space with a convergence structure to locate zeros of operators. P. Meyer introduced the concept of a Banach space with a convergence structure. Using this setting, he presented a finer semilocal convergence analysis for Newton's method than in related studies using the real norm theory. In all these studies the operator involved as well as its Fréchet derivative is bounded above by the same bound-operator. In the present study, we introduce a second bound operator which is a special case of the bound-operator leading to tighter majorizing sequences for Newton's method. Using this more flexible combination of bound-operators, we improve the results in the earlier studies. In the semilocal case, we obtain under the same or weaker sufficient convergence conditions more precise error bounds on the distances involved and in the local case not considered in the earlier studies, we obtain a larger radius of convergence. This way we expand the applicability of Newton's method. Some numerical examples are also provided to show the superiority of the new results over the old results. [ABSTRACT FROM AUTHOR]

We present a weaker convergence analysis of Newton’s method than in Kantorovich and Akilov (1964), Meyer (1987), Potra and Ptak (1984), Rheinboldt (1978), Traub (1964) on a generalized Banach space setting to approximate a locally unique zero of an operator. This way we extend the applicability of Newton’s method. Moreover, we obtain under the same conditions in the semilocal case weaker sufficient convergence criteria; tighter error bounds on the distances involved and an at least as precise information on the location of the solution. In the local case we obtain a larger radius of convergence and higher error estimates on the distances involved. Numerical examples illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

We present a new semilocal convergence analysis for Newton-like methods in order to approximate a locally unique solution of an equation in a Banach space setting. This way, we expand the applicability of these methods in cases not covered in earlier studies. The advantages of our approach include a more precise convergence analysis under the same computational cost on the Lipschitz constants involved. Applications are also given in this study to show that our estimates on the distances involved are tighter than the older ones. [ABSTRACT FROM AUTHOR]

The semilocal and local convergence in Banach spaces is described for a fifth order iteration for the solutions of nonlinear equations when the Fréchet derivative satisfies the Hölder condition. The Hölder condition generalizes the Lipschtiz condition. The importance of our work lies in the fact that many examples are available which fail to satisfy the Lipschtiz condition but satisfy the Hölder condition. The existence and uniqueness theorem is established with error bounds for the solution. The convergence analysis is finally worked out on different examples and convergence balls for each of them are obtained. These examples include nonlinear Hammerstein and Fredholm integral equations and a boundary value problem. It is found that the larger radius of convergence balls is obtained for all the examples in comparison to existing methods using stronger conditions. [ABSTRACT FROM AUTHOR]

The construction of initial conditions of an iterative method is one of the most important problems in solving nonlinear equations. In this paper, we obtain relationships between different types of initial conditions that guarantee the convergence of iterative methods for simultaneously finding all zeros of a polynomial. In particular, we show that any local convergence theorem for a simultaneous method can be converted into a convergence theorem with computationally verifiable initial conditions which is of practical importance. Thus, we propose a new approach for obtaining semilocal convergence results for simultaneous methods via local convergence results. [ABSTRACT FROM AUTHOR]

Kyurkchiev and Andreev (1985) constructed an infinite sequence of Weierstrass-type iterative methods for approximating all zeros of a polynomial simultaneously. The first member of this sequence of iterative methods is the famous method of Weierstrass (1891) and the second one is the method of Nourein (1977). For a given integer N ≥ 1, the N th method of this family has the order of convergence N + 1 . Currently in the literature, there are only local convergence results for these methods. The main purpose of this paper is to present semilocal convergence results for the Weierstrass-type methods under computationally verifiable initial conditions and with computationally verifiable a posteriori error estimates. [ABSTRACT FROM AUTHOR]

In this paper we study the convergence of Halley's method as a method for finding all zeros of a polynomial simultaneously. We present two types of local convergence theorems as well as a semilocal convergence theorem for Halley's method for simultaneous computation of polynomial zeros. [ABSTRACT FROM AUTHOR]

We study a family of high-order Ehrlich-type methods for approximating all zeros of a polynomial simultaneously. Let us denote by $T^{(1)}$ the famous Ehrlich method (1967). Starting from $T^{(1)}$, Kjurkchiev and Andreev (1987) have introduced recursively a sequence ${(T^{(N)})_{N = 1}^{\infty}}$ of iterative methods for simultaneous finding polynomial zeros. For given $N \ge1$, the Ehrlich-type method $T^{(N)}$ has the order of convergence ${2 N + 1}$. In this paper, we establish two new local convergence theorems as well as a semilocal convergence theorem (under computationally verifiable initial conditions and with an a posteriori error estimate) for the Ehrlich-type methods $T^{(N)}$. Our first local convergence theorem generalizes a result of Proinov (2015) and improves the result of Kjurkchiev and Andreev (1987). The second local convergence theorem generalizes another recent result of Proinov (2015), but only in the case of the maximum norm. Our semilocal convergence theorem is the first result in this direction. [ABSTRACT FROM AUTHOR]

We present a new semilocal convergence analysis for Secant method in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. Our analysis includes the computation of the bounds on the limit points of the majorizing sequences involved. Under the same computational cost on the parameters involved our convergence criteria are weaker and the error bounds more precise than in earlier studies such as (Amat and Busquier, 2003; Amat et al., in press; Argyros and Hilout, 2012; Argyros et al., 2014; Argyros and Magreñán, 2014, 2015; Dennis, 1971; Ezquerro et al., 2000; Ortega and Rheinboldt, 1970; Potra and Pták, 1984; Schmidt, 1978). Numerical examples are also presented to illustrate the theoretical results obtained in this study. [ABSTRACT FROM AUTHOR]

We present a unified convergence analysis of Inexact Newton-like methods in order to approximate a locally unique solution of a nonlinear operator equation containing a nondifferentiable term in a Banach space setting. The convergence conditions are more general and the error analysis more precise than in earlier studies such as (Argyros, 2007; Cătinaş, 2005; Cătinaş, 1994; Chen and Yamamoto, 1989; Dennis, 1968; Hernández and Romero, 2005; Potra and Pták, 1984; Rheinboldt, 1977). Special cases of our results can be used to find zeros of derivatives. Numerical examples are also provided in this study. [ABSTRACT FROM AUTHOR]

Abstract: We present sufficient convergence conditions for two-step Newton methods in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. The advantages of our approach over other studies such as Argyros et al. (2010) [5], Chen et al. (2010) [11], Ezquerro et al. (2000) [16], Ezquerro et al. (2009) [15], Hernández and Romero (2005) [18], Kantorovich and Akilov (1982) [19], Parida and Gupta (2007) [21], Potra (1982) [23], Proinov (2010) [25], Traub (1964) [26] for the semilocal convergence case are: weaker sufficient convergence conditions, more precise error bounds on the distances involved and at least as precise information on the location of the solution. In the local convergence case more precise error estimates are presented. These advantages are obtained under the same computational cost as in the earlier stated studies. Numerical examples involving Hammerstein nonlinear integral equations where the older convergence conditions are not satisfied but the new conditions are satisfied are also presented in this study for the semilocal convergence case. In the local case, numerical examples and a larger convergence ball are obtained. [Copyright &y& Elsevier]

We present a unified local and semilocal convergence analysis for secant-type methods in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. Our analysis includes the computation of the bounds on the limit points of the majorizing sequences involved. Under the same computational cost, using both Lipschtiz and center Lipschitz conditions, our convergence criteria can be: weaker; the error bounds more precise and the convergence balls larger than in earlier studies. Special cases such us Newton's method or Secant method are also presented. Numerical examples, including a Chandrasekhar equation and a boundary value problem, are also presented to illustrate the theoretical results obtained in this study. [ABSTRACT FROM AUTHOR]

In this paper we present new local and semilocal convergence theorems for the two-point Weierstrass method for the simultaneous computation of polynomial zeros. Our local convergence result improves and complements the previous one obtained by Kanno et al. (Jpn J Indus Appl Math 13, 267-288, ). [ABSTRACT FROM AUTHOR]

We present a local as well as a semilocal convergence analysis for Newton’s method for approximating a locally unique solution of a nonlinear equation in a Banach space setting. Our hypotheses involve m-Fréchet-differentiable operators and general Lipschitz-type hypotheses, where m≥2 is a positive integer. The new convergence analysis unifies earlier results; it is more flexible and provides a finer convergence analysis than in earlier studies such as Argyros in J. Comput. Appl. Math. 131:149–159, 2001 , Argyros and Hilout in J. Appl. Math. Comput. 29:391–400, 2009 , Argyros and Hilout in J. Complex. 28:364–387, 2012 , Argyros et al. Numerical Methods for Equations and Its Applications, CRC Press/Taylor & Francis, New York, 2012 , Gutiérrez in J. Comput. Appl. Math. 79:131–145, 1997 , Ren and Argyros in Appl. Math. Comput. 217:612–621, 2010 , Traub and Wozniakowski in J. Assoc. Comput. Mech. 26:250–258, 1979 . Numerical examples are presented further validating the theoretical results. [ABSTRACT FROM AUTHOR]

Abstract: The famous Newton–Kantorovich hypothesis has been used for a long time as a sufficient condition for the convergence of Newton''s method to a solution of an equation. Here we present a “Kantorovich type” convergence analysis for the Gauss–Newton''s method which improves the result in [W.M. Häußler, A Kantorovich-type convergence analysis for the Gauss–Newton-method, Numer. Math. 48 (1986) 119–125.] and extends the main theorem in [I.K. Argyros, On the Newton-Kantorovich hypothesis for solving equations, J. Comput. Appl. Math. 169 (2004) 315–332]. Furthermore, the radius of convergence ball is also obtained. [Copyright &y& Elsevier]

We introduce a new iterative method of asymptotic order 1+√2 for approximating fixed points of non-linear equations in a Banach space as well as in a partially topological space. The method requires less computational cost than others in the literature and uses only divided differences of order 1. [ABSTRACT FROM AUTHOR]

In this paper, we construct and study a new family of multi-point Ehrlich-type iterative methods for approximating all the zeros of a uni-variate polynomial simultaneously. The first member of this family is the two-point Ehrlich-type iterative method introduced and studied by Trićković and Petković in 1999. The main purpose of the paper is to provide local and semilocal convergence analysis of the multi-point Ehrlich-type methods. Our local convergence theorem is obtained by an approach that was introduced by the authors in 2020. Two numerical examples are presented to show the applicability of our semilocal convergence theorem. [ABSTRACT FROM AUTHOR]

In 1977, Nourein (Intern. J. Comput. Math. 6:3, 1977) constructed a fourth-order iterative method for finding all zeros of a polynomial simultaneously. This method is also known as Ehrlich's method with Newton's correction because it is obtained by combining Ehrlich's method (Commun. ACM 10:2, 1967) and the classical Newton's method. The paper provides a detailed local convergence analysis of a well-known but not well-studied generalization of Nourein's method for simultaneous finding of multiple polynomial zeros. As a consequence, we obtain two types of local convergence theorems as well as semilocal convergence theorems (with verifiable initial condition and a posteriori error bound) for the classical Nourein's method. Each of the new semilocal convergence results improves the result of Petković, Petković and Rančić (J. Comput. Appl. Math. 205:1, 2007) in several directions. The paper ends with several examples that show the applicability of our semilocal convergence theorems. [ABSTRACT FROM AUTHOR]

This paper is devoted to a family of Newton-like methods with frozen derivatives used to approximate a locally unique solution of an equation. We perform a convergence study and an analysis of the efficiency. This analysis gives us the opportunity to select the most efficient method in the family without the necessity of their implementation. The method can be applied to many type of problems, including the discretization of ordinary differential equations, integral equations, integro-differential equations or partial differential equations. Moreover, multi-step iterative methods are computationally attractive. [ABSTRACT FROM AUTHOR]