scholarly journals Improved Iterative Solution of Linear Fredholm Integral Equations of Second Kind via Inverse-Free Iterative Schemes

Mathematics ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1747
Author(s):  
José Manuel Gutiérrez ◽  
Miguel Ángel Hernández-Verón ◽  
Eulalia Martínez
Keyword(s):  
Integral Equations ◽  
Theoretical Study ◽  
Iterative Scheme ◽  
Semilocal Convergence ◽  
Iterative Solution ◽  
Fredholm Integral Equations ◽  
Existence Of A Solution ◽  
Separable Kernel ◽  
Starting Point ◽  
Domain Of Existence

This work is devoted to Fredholm integral equations of second kind with non-separable kernels. Our strategy is to approximate the non-separable kernel by using an adequate Taylor’s development. Then, we adapt an already known technique used for separable kernels to our case. First, we study the local convergence of the proposed iterative scheme, so we obtain a ball of starting points around the solution. Then, we complete the theoretical study with the semilocal convergence analysis, that allow us to obtain the domain of existence for the solution in terms of the starting point. In this case, the existence of a solution is deduced. Finally, we illustrate this study with some numerical experiments.

scholarly journals An Ulm-Type Inverse-Free Iterative Scheme for Fredholm Integral Equations of Second Kind

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1957
Author(s):  
José M. Gutiérrez ◽  
Miguel Á. Hernández-Verón
Keyword(s):  
Integral Equations ◽  
Order Of Convergence ◽  
Iterative Scheme ◽  
Semilocal Convergence ◽  
Fredholm Integral Equations ◽  
Linear Integral ◽  
Ulm’S Method ◽  
Theoretical Results ◽  
Quadratic Order ◽  
Linear Integral Equations

In this paper, we present an iterative method based on the well-known Ulm’s method to numerically solve Fredholm integral equations of the second kind. We support our strategy in the symmetry between two well-known problems in Numerical Analysis: the solution of linear integral equations and the approximation of inverse operators. In this way, we obtain a two-folded algorithm that allows us to approximate, with quadratic order of convergence, the solution of the integral equation as well as the inverses at the solution of the derivative of the operator related to the problem. We have studied the semilocal convergence of the method and we have obtained the expression of the method in a particular case, given by some adequate initial choices. The theoretical results are illustrated with two applications to integral equations, given by symmetric non-separable kernels.

scholarly journals Study on the Accuracy Improvement of the Second-Kind Fredholm Integral Equations by Using the Buffa-Christiansen Functions with MLFMA

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Yue-Qian Wu ◽  
Xin-Qing Sheng ◽  
Xing-Yue Guo ◽  
Hai-Jing Zhou
Keyword(s):  
Integral Equations ◽  
Iterative Solution ◽  
Fredholm Integral Equations ◽  
Accuracy Improvement ◽  
Electric Conductor ◽  
Triangular Elements ◽  
Fast Multipole Algorithm ◽  
Magnetic Field Integral Equation ◽  
The Magnetic Field ◽  
Better Than

Former works show that the accuracy of the second-kind integral equations can be improved dramatically by using the rotated Buffa-Christiansen (BC) functions as the testing functions, and sometimes their accuracy can be even better than the first-kind integral equations. When the rotated BC functions are used as the testing functions, the discretization error of the identity operators involved in the second-kind integral equations can be suppressed significantly. However, the sizes of spherical objects which were analyzed are relatively small. Numerical capability of the method of moments (MoM) for solving integral equations with the rotated BC functions is severely limited. Hence, the performance of BC functions for accuracy improvement of electrically large objects is not studied. In this paper, the multilevel fast multipole algorithm (MLFMA) is employed to accelerate iterative solution of the magnetic-field integral equation (MFIE). Then a series of numerical experiments are performed to study accuracy improvement of MFIE in perfect electric conductor (PEC) cases with the rotated BC as testing functions. Numerical results show that the effect of accuracy improvement by using the rotated BC as the testing functions is greatly different with curvilinear or plane triangular elements but falls off when the size of the object is large.

scholarly journals A Picard-Type Iterative Scheme for Fredholm Integral Equations of the Second Kind

Mathematics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 83
Author(s):  
José M. Gutiérrez ◽  
Miguel Á. Hernández-Verón
Keyword(s):  
Iterative Method ◽  
Banach Spaces ◽  
Integral Equations ◽  
Nonlinear Equations ◽  
Newton’S Method ◽  
Newton's Method ◽  
Quadratic Convergence ◽  
Iterative Scheme ◽  
Fredholm Integral Equations

In this work, we present an application of Newton’s method for solving nonlinear equations in Banach spaces to a particular problem: the approximation of the inverse operators that appear in the solution of Fredholm integral equations. Therefore, we construct an iterative method with quadratic convergence that does not use either derivatives or inverse operators. Consequently, this new procedure is especially useful for solving non-homogeneous Fredholm integral equations of the first kind. We combine this method with a technique to find the solution of Fredholm integral equations with separable kernels to obtain a procedure that allows us to approach the solution when the kernel is non-separable.

scholarly journals Semilocal Convergence of the Extension of Chun’s Method

Axioms ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 161
Author(s):  
Alicia Cordero ◽  
Javier G. Maimó ◽  
Eulalia Martínez ◽  
Juan R. Torregrosa ◽  
María P. Vassileva
Keyword(s):  
Iterative Method ◽  
Existence And Uniqueness ◽  
Recurrence Relations ◽  
Nonlinear Integral Equation ◽  
Difference Operator ◽  
Divided Difference ◽  
Semilocal Convergence ◽  
Starting Point ◽  
Domain Of Existence ◽  
Theoretical Results

In this work, we use the technique of recurrence relations to prove the semilocal convergence in Banach spaces of the multidimensional extension of Chun’s iterative method. This is an iterative method of fourth order, that can be transferred to the multivariable case by using the divided difference operator. We obtain the domain of existence and uniqueness by taking a suitable starting point and imposing a Lipschitz condition to the first Fréchet derivative in the whole domain. Moreover, we apply the theoretical results obtained to a nonlinear integral equation of Hammerstein type, showing the applicability of our results.

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