We estimate the distribution function of a Lagrange interpolation polynomial and deduce mean boundedness in L p , p<1. 1999 Academic Press ## 1. THE RESULT There is a vast literature on mean convergence of Lagrange interpolation, see [4 8] for recent references. In this note, we use distribution
Notes on Steklov's Conjecture inLpand on Divergence of Lagrange Interpolation inLp
โ Scribed by Paul Nevai; Ying Guang Shi
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 248 KB
- Volume
- 90
- Category
- Article
- ISSN
- 0021-9045
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โฆ Synopsis
Given a compact interval 2, it is shown that for E. A. Rakhmanov's weight w on 2 which is bounded from below by the Chebyshev weight v on 2 (1982, Math. USSR Sb. 42, 263) the corresponding orthonormal polynomials are unbounded in every L p v (and L p w ) with p>2 and also that the Lagrange interpolation process based on their zeros diverges in every L p v with p>2 for some continuous f . This yields an affirmative answer to Conjecture 2.9 in ``Research Problems in
๐ SIMILAR VOLUMES
It is a classical result of Bernstein that the sequence of Lagrange interpolation polynomials to \(|x|\) at equally spaced nodes in \([-1,1]\) diverges everywhere, except at zero and the end-points. In the present paper we show that the case of equally spaced nodes is not an exceptional one in this