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arXiv · 2610.41660

Elliptic Fekete points: separation, Riesz energies, and polynomial conditioning

Ujué Etayo
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Abstract

Elliptic Fekete configurations minimize logarithmic energy on the sphere. They also provide a natural source of complex polynomials with controlled Shub--Smale condition number. The link between these two problems is the product of the distances from each point to all the other points: logarithmic energy controls the geometric mean of these products, whereas local conditioning depends on each product separately. This paper studies the passage from global information to uniform estimates at individual nodes, exploring its connections with quantitative equidistribution, Riesz energies, and polynomial conditioning. We improve separation bounds for elliptic Fekete configurations and obtain quantitative Riesz-energy estimates for both these configurations and spherical roots of polynomials with optimal-order global conditioning. For $0<s<2$, these estimates also improve explicit upper bounds for the minimal Riesz $s$-energy.

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Ujué Etayo. 2026-10-30. Elliptic Fekete points: separation, Riesz energies, and polynomial conditioning. https://arxiv.org/abs/2610.41660

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