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This article is cited in 1 scientific paper (total in 1 paper)
Convergence of Trigonometric Fourier Series of Functions with a Constraint on the Fractality of Their Graphs
M. L. Gridnev Institute of Mathematics and Mechanics, Ural Branch of the Russian Academy of Sciences, Ekaterinburg
Abstract:
For a function f continuous on a closed interval, its modulus of fractality ν(f,ε) is defined as the function that maps any ε>0 to the smallest number of squares of size ε that cover the graph of f. The following condition for the uniform convergence of the Fourier series of f is obtained in terms of the modulus of fractality and the modulus of continuity ω(f,δ): if
$$
\omega (f,\pi/n) \ln\bigg(\frac{\nu(f,\pi/n)}{n}\bigg) \longrightarrow 0\ \ \ as \ n\longrightarrow+\infty,
$$
then the Fourier series of f converges uniformly. This condition refines the known Dini–Lipschitz test. In addition, for the growth order of the partial sums Sn(f,x) of a continuous function f, we derive an estimate that is uniform in x∈[0,2π]:
Sn(f,x)=o(ln(ν(f,π/n)n)).
The optimality of this estimate is shown.
Keywords:
trigonometric Fourier series, uniform convergence, fractal dimension.
Received: 31.08.2018 Revised: 28.10.2018 Accepted: 05.11.2018
Citation:
M. L. Gridnev, “Convergence of Trigonometric Fourier Series of Functions with a Constraint on the Fractality of Their Graphs”, Trudy Inst. Mat. i Mekh. UrO RAN, 24, no. 4, 2018, 104–109; Proc. Steklov Inst. Math. (Suppl.), 308, suppl. 1 (2020), S106–S111
Linking options:
https://www.mathnet.ru/eng/timm1578 https://www.mathnet.ru/eng/timm/v24/i4/p104
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Abstract page: | 281 | Full-text PDF : | 83 | References: | 50 | First page: | 2 |
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