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On Approximation by Fejér Means to Periodic Functions Satisfying a Lipschitz Condition

Published online by Cambridge University Press:  20 November 2018

Lee Lorch*
Affiliation:
University of Alberta, Edmonton
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S. M. Nikolski [4, Theorem 1; cf. 3, esp. pp. 144 and 148] considered the remainder term in the approximation by the n-th Fejér mean, σn(x), to a function, f(x), of period 2π satisfying a Lipschitz condition of order α, 0<α≤1. In this connection, he introduced the quantity

1

where the maximum is taken over all x and the supremum is taken over all functions of period 2π, bounded by 1 (a notational convenience only) and satisfying a Laps chitz condition of order α.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1962

References

1. Lee, Lorch, Asymptotic Expressions for some Integrals which include certain Lebesgue and Féjer Constants, Duke Math. Journal, vol. 20(1953), pp. 89-104.Google Scholar
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