Abstract
In the Hilbert spaceL 2(Δ2), Δ = [0, 2 π] we establish exact estimates of the Kolmogorov quasiwidths of some classes of periodic functions of two variables whose averaged modules of smoothness of mixed derivatives are majorizable by given functions.
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Vakarchuk, S.B., Shabozov, M.S. On exact values of quasiwidths of some classes of functions. Ukr Math J 48, 338–346 (1996). https://doi.org/10.1007/BF02378524
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DOI: https://doi.org/10.1007/BF02378524