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Representation and approximation of multivariate periodic functions with bounded mixed moduli of smoothness. (English) Zbl 1032.42015

Proc. Steklov Inst. Math. 219, 350-371 (1997) and Tr. Mat. Inst. Steklova 219, 356-377 (1997).
The authors introduce the Besov class \(B^\Omega_{q,\theta}(\pi_d)\) as an extension of the class \(S^r_{q,\theta}(\pi_d)\) investigated by T. I. Amanov [Proc. Steklov Inst. Math. 77, 3-36 (1965); translation from Tr. Mat. Inst. Steklova 77, 5-34 (1965; Zbl 0152.12701)], and prove representation theorems for this class, approximation theorems on approximation of functions from \(B^\Omega_{q,\theta}(\pi_d)\) by Fourier sums of hyperbolic-cross type and asymptotic estimates of the Kolmogorov \(N\)-width \(d_N(B^\Omega_{q,\theta}, L_p)\).
For the entire collection see [Zbl 0907.00017].

MSC:

42B05 Fourier series and coefficients in several variables
41A46 Approximation by arbitrary nonlinear expressions; widths and entropy
41A65 Abstract approximation theory (approximation in normed linear spaces and other abstract spaces)

Citations:

Zbl 0152.12701