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Asymptotics of sharp constants of Markov-Bernstein inequalities in integral norm with Jacobi weight

2014/05/01 by A. I. Aptekarev, A. Draux, Aptekarev, A. I. +5
Mathematics · #33C45 #41A20.21 #42C05 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #math.CA #msc:33C45 #msc:41A20.21 #msc:42C05

paper · pdf · doi:10.48550/arxiv.1405.0167

12 pages, biblio 15 sources

arxiv created 2014/05/01 · arxiv updated 2014/05/02

Abstract

The classical A. Markov inequality establishes a relation between the maximum modulus or the L([-1,1]) norm of a polynomial Qn and of its derivative: ‖Q'n‖\leqslant Mn n2‖Qn‖, where the constant Mn=1 is sharp. The limiting behavior of the sharp constants Mn for this inequality, considered in the space L2([-1,1], w(α,β)) with respect to the classical Jacobi weight w(α,β)(x):=(1-x)α(x+1)β, is studied. We prove that, under the condition |α- β| < 4 , the limit is limn → ∞ Mn = 1/(2 jν) where jν is the smallest zero of the Bessel function Jν(x) and 2 ν= min(α, β) - 1.

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