On the Lebesgue Inequality on Classes of $\bar{\psi}$ -Differentiable Functions

• Date: 2013
• Main Authors: Zaderei, N. N., Zaderei, P. V., Задерей, Н. М., Задерей, П. В.
• Format: Article
• Language: Ukrainian; English
• Published: Institute of Mathematics, NAS of Ukraine 2013
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/2469
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

We consider the deviations of Fourier sums in the spaces ${C^{\bar{\psi}}}$. The estimates of these deviations are expressed via the best approximations of the $\bar{\psi}$ -derivatives of functions in the Stepanets sense. The sequences $\bar{\psi} = (ψ_1, ψ_2)$ are quasiconvex.