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This article is cited in 3 scientific papers (total in 3 papers)
Fractional derivatives and inequalities for trigonometric polynomials in spaces with asymmetric norms
A. I. Kozko M. V. Lomonosov Moscow State University
Abstract:
We consider the Bernstein–Jackson–Nikol'skii inequalities for fractional derivatives in the case when the norm is asymmetric. Assume that $n\in\mathbb N$, $p_1,p_2,q_1,q_2\in[1,\infty]$, and $\alpha\in\mathbb R_+$. Then
$$
\sup_{\substack t_n\in\tau_n\\t_n\not\equiv 0}\dfrac{\|D^\alpha t_n\|_{q_1,q_2}}{\|t_n\|_{p_1,p_2}}\asymp I_\alpha n^{\alpha+\psi_1(p_1,p_2,q_1,q_2)}+n^{\alpha+\psi_2(p_1,p_2,q_1,q_2)},
$$
where
$$
I_\alpha=\begin{cases}
\alpha,&0\leqslant\alpha\leqslant 1,\\ 1,&\alpha\geqslant 1,
\end{cases}
$$
and the functions $\psi_1$ and $\psi_2$ are given by an explicit formula. The asymptotic behaviour is with respect to $n$ for fixed $\alpha$, $p_1$, $p_2$, $q_1$ and $q_2$.
Received: 17.07.1997
Citation:
A. I. Kozko, “Fractional derivatives and inequalities for trigonometric polynomials in spaces with asymmetric norms”, Izv. Math., 62:6 (1998), 1189–1206
Linking options:
https://www.mathnet.ru/eng/im223https://doi.org/10.1070/im1998v062n06ABEH000223 https://www.mathnet.ru/eng/im/v62/i6/p125
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