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arXiv · 2403.09378

The Fekete problem in segmental polynomial interpolation

Ludovico Bruni Bruno·Wolfgang Erb
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Abstract

In this article, we study the Fekete problem in segmental and combined nodal-segmental univariate polynomial interpolation by investigating sets of segments, or segments combined with nodes, such that the Vandermonde determinant for the respective polynomial interpolation problem is maximized. For particular families of segments, we will be able to find explicit solutions of the corresponding maximization problem. The quality of the Fekete segments depends hereby strongly on the utilized normalization of the segmental information in the Vandermonde matrix. To measure the quality of the Fekete segments in interpolation, we analyse the asymptotic behaviour of the generalized Lebesgue constant linked to the interpolation problem. For particular sets of Fekete segments we will get, similar to the nodal case, a favourable logarithmic growth of this constant.

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Ludovico Bruni Bruno, Wolfgang Erb. 2024-03-14. The Fekete problem in segmental polynomial interpolation. https://arxiv.org/abs/2403.09378

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