Analogs of the Jackson–Nikol'skii inequalities for trigonometric polynomials in spaces with nonsymmetric norm
Matematičeskie zametki, Tome 61 (1997) no. 5, pp. 687-699
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The paper is concerned with the evaluation of $$ \sup_{\substack{t_n\in T_n\\t _n\not\equiv 0}} \frac{\|t_n\|_{q_1,q_2}}{\|t_n\|_{p_1,p_2}}, $$ where $\|\cdot\|_{p_1,p_2}$ is a nonsymmetric norm. The order of this number is obtained. Lower bounds involve new polynomials whose properties are studied in detail. In the case $p_1=p_2$, $q_1=q_2$, the estimate obtained is reduced to the well-known Jackson–Nikol'skii inequality.
@article{MZM_1997_61_5_a5,
author = {A. I. Kozko},
title = {Analogs of the {Jackson{\textendash}Nikol'skii} inequalities for trigonometric polynomials in spaces with nonsymmetric norm},
journal = {Matemati\v{c}eskie zametki},
pages = {687--699},
year = {1997},
volume = {61},
number = {5},
language = {ru},
url = {http://geodesic.mathdoc.fr/item/MZM_1997_61_5_a5/}
}
TY - JOUR AU - A. I. Kozko TI - Analogs of the Jackson–Nikol'skii inequalities for trigonometric polynomials in spaces with nonsymmetric norm JO - Matematičeskie zametki PY - 1997 SP - 687 EP - 699 VL - 61 IS - 5 UR - http://geodesic.mathdoc.fr/item/MZM_1997_61_5_a5/ LA - ru ID - MZM_1997_61_5_a5 ER -
A. I. Kozko. Analogs of the Jackson–Nikol'skii inequalities for trigonometric polynomials in spaces with nonsymmetric norm. Matematičeskie zametki, Tome 61 (1997) no. 5, pp. 687-699. http://geodesic.mathdoc.fr/item/MZM_1997_61_5_a5/
[1] Nikolskii S. M., Priblizhenie funktsii mnogikh peremennykh i teoremy vlozheniya, Nauka, M., 1977
[2] Jackson D., “Certain problem of closest approximation”, Bull. Amer. Math. Soc., 39 (1933), 889–906 | DOI | Zbl
[3] Stechkin S. B., “Obobschenie nekotorykh neravenstv S. N. Bernshteina”, Dokl. AN SSSR, 60:9 (1948), 1511–1514 | MR | Zbl
[4] Dzyadyk V. K., Vvedenie v teoriyu ravnomernogo priblizheniya funktsii polinomami, Nauka, M., 1977 | Zbl
[5] Timan A. F., Teoriya priblizhenii funktsii deistvitelnogo peremennogo, Fizmatgiz, M., 1960