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arXiv · 2009.09711

Positivity of Tur\'an determinants for orthogonal polynomials II

Ryszard Szwarc
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Abstract

The polynomials $p_n$ orthogonal on the interval $[-1,1],$ normalized by $p_n(1)=1,$ satisfy Tur\'an's inequality if $p_n^2(x)-p_{n-1}(x)p_{n+1}(x)\ge 0$ for $n\ge 1$ and for all $x$ in the interval of orthogonality. We give a general criterion for orthogonal polynomials to satisfy Tur\'an's inequality. This extends essentially the results of \cite{szw}. In particular the results can be applied to many classes of orthogonal polynomials, by inspecting their recurrence relation.

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Ryszard Szwarc. 2020-09-21. Positivity of Tur\'an determinants for orthogonal polynomials II. https://arxiv.org/abs/2009.09711

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