Abstract:
Necessary and sufficient conditions for the accuracy of embedding theorems of various function classes are obtained. The main result of the paper is a criterion for embeddings between generalized Weyl-Nikol'skiǐ and generalized Lipschitz classes. To define the Weyl-Nikol'skiǐ classes we use the concept of
a (λ,β)-derivative, which is a generalization of the derivative in the sense of Weyl. As corollaries,
estimates for the norms and moduli of smoothness of transformed Fourier series are obtained.
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