Accelerated Landweber methods based on co-dilated orthogonal polynomials

Wolfgang Erb

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arXiv · 1206.1950

Accelerated Landweber methods based on co-dilated orthogonal polynomials

Wolfgang Erb

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Abstract

In this article, we introduce and study accelerated Landweber methods for linear ill-posed problems obtained by an alteration of the coefficients in the three-term recurrence relation of the \nu-methods. The residual polynomials of the semi-iterative methods under consideration are linked to a family of co-dilated ultraspherical polynomials. This connection makes it possible to increase the decay of the residual polynomials at the origin by means of a dilation parameter. This increased decay has advantages when solving linear ill-posed equations in which the spectrum of the involved operators is clustered at the origin. The convergence order of the new semi-iterative methods turns out to be the same as the convergence order of the original \nu-methods. The new algorithms are tested numerically and a simple adaptive scheme is developed in which an optimal dilation parameter is computed.

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Wolfgang Erb. 2012-06-09. Accelerated Landweber methods based on co-dilated orthogonal polynomials. https://arxiv.org/abs/1206.1950

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