In order to approximate functions defined on the real semiaxis, which can grow exponentially both at $0$ and at $+infty$, we introduce a suitable Lagrange operator based on the zeros of orthogonal polynomials with respect to the weight $w(x)=x^gamma mathrm{e}^{-x^{-alpha}-x^eta}$. We prove that this interpolation process has Lebesgue constant with order $log(m)$ in weighted uniform metric and converges with the order of the best approximation in a large subset of weighted $L^p-$spaces, $p in (1,infty)$

Lagrange interpolation at Pollaczek--Laguerre zeros on the real semiaxis

Notarangelo I.
2019-01-01

Abstract

In order to approximate functions defined on the real semiaxis, which can grow exponentially both at $0$ and at $+infty$, we introduce a suitable Lagrange operator based on the zeros of orthogonal polynomials with respect to the weight $w(x)=x^gamma mathrm{e}^{-x^{-alpha}-x^eta}$. We prove that this interpolation process has Lebesgue constant with order $log(m)$ in weighted uniform metric and converges with the order of the best approximation in a large subset of weighted $L^p-$spaces, $p in (1,infty)$
2019
245
83
100
https://www.sciencedirect.com/science/article/abs/pii/S0021904519300425
https://www.sciencedirect.com/journal/journal-of-approximation-theory
Lagrange interpolation; Orthogonal polynomials; Pollaczek–Laguerre exponential weights; Real semiaxis; Weighted polynomial approximation
Mastroianni G.; Notarangelo I.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1724928
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