caa a22 4500 475741862 CHVBK 20180406123501.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1007/BF02676409 doi (NATIONALLICENCE)springer-10.1007/BF02676409 Khatamov A. A. Navoi Samarkand State University, USSR aut Multidimensional analogs of direct and converse Jackson and Bernshtein theorems and their generalizations [Elektronische Daten] [A. Khatamov] We obtain an instance of the multidimensional analogs of the classical direct and converse Jackson and Bernshtein-Vallée-Poussin theorems (a version stronger than those obtained by S. M. Nikol'skii) and significant generalizations of these theorems to polynomial approximations of functions of real variables from Nikol'skii and Besov spaces on bounded domains with Lipschitzian boundary. The direct theorem concerning the Nikol'skii spaces was previously obtained by Yu. A. Brudnyi and generalized to joint polynomial approximations of functions and their derivatives by B. N. Konovalov. Kluwer Academic/Plenum Publishers, 2000 polynomial approximation nationallicence function of real variables nationallicence direct and converse Jackson and Bernshtein-Vallée-Poussin theorems nationallicence Besov space nationallicence Nikol'skii space nationallicence Mathematical Notes Kluwer Academic Publishers-Plenum Publishers 67/4(2000-04-01), 516-522 0001-4346 67:4<516 2000 67 11006 https://doi.org/10.1007/BF02676409 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02676409 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Khatamov A. A. Navoi Samarkand State University, USSR aut NATIONALLICENCE 773 0- Mathematical Notes Kluwer Academic Publishers-Plenum Publishers 67/4(2000-04-01), 516-522 0001-4346 67:4<516 2000 67 11006 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer