Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Pointwise Remez inequality
AU - Eichinger, B.
AU - Yuditskii, P.
N1 - Publisher Copyright: © 2021, The Author(s).
PY - 2021/12/31
Y1 - 2021/12/31
N2 - The standard well-known Remez inequality gives an upper estimate of the values of polynomials on [- 1 , 1] if they are bounded by 1 on a subset of [- 1 , 1] of fixed Lebesgue measure. The extremal solution is given by the rescaled Chebyshev polynomials for one interval. Andrievskii asked about the maximal value of polynomials at a fixed point, if they are again bounded by 1 on a set of fixed size. We show that the extremal polynomials are either Chebyshev (one interval) or Akhiezer polynomials (two intervals) and prove Totik–Widom bounds for the extremal value, thereby providing a complete asymptotic solution to the Andrievskii problem.
AB - The standard well-known Remez inequality gives an upper estimate of the values of polynomials on [- 1 , 1] if they are bounded by 1 on a subset of [- 1 , 1] of fixed Lebesgue measure. The extremal solution is given by the rescaled Chebyshev polynomials for one interval. Andrievskii asked about the maximal value of polynomials at a fixed point, if they are again bounded by 1 on a set of fixed size. We show that the extremal polynomials are either Chebyshev (one interval) or Akhiezer polynomials (two intervals) and prove Totik–Widom bounds for the extremal value, thereby providing a complete asymptotic solution to the Andrievskii problem.
KW - Chebyshev and Akhiezer polynomials
KW - Comb domains
KW - Remez inequality
KW - Totik–Widom bounds
U2 - 10.1007/s00365-021-09562-1
DO - 10.1007/s00365-021-09562-1
M3 - Journal article
AN - SCOPUS:85118598857
VL - 54
SP - 529
EP - 554
JO - Constructive Approximation
JF - Constructive Approximation
SN - 0176-4276
IS - 3
ER -