; and the Hardy–Besov space $B^\alpha _p$, $\alpha \ge 0$, $0 . It is shown that if all the poles of the rational function $R$ of degree $n$, $n=1,2,3,\dots $, lie in the domain $|z|>1$, then $\|R\|_{H^\alpha _{1/\alpha }}\le cn^\alpha \|R\|_{\mathscr B}$, $\|R\|_{B^\alpha _{1/\alpha }}\le cn^\alpha \|R\|_{\mathscr B}$, where $\alpha >0$ and $c >0$ depends only on $\alpha$ . The second of these inequalities for the case of the half-plane was obtained by Semmes in 1984. The proof given by Semmes was based on the use of Hankel operators, while our proof uses the special integral representation of rational functions.
@article{MZM_2002_72_2_a8,
author = {A. A. Pekarskii},
title = {New {Proof} of the {Semmes} {Inequality} for the {Derivative} of the {Rational} {Function}},
journal = {Matemati\v{c}eskie zametki},
pages = {258--264},
year = {2002},
volume = {72},
number = {2},
language = {ru},
url = {http://geodesic.mathdoc.fr/item/MZM_2002_72_2_a8/}
}
A. A. Pekarskii. New Proof of the Semmes Inequality for the Derivative of the Rational Function. Matematičeskie zametki, Tome 72 (2002) no. 2, pp. 258-264. http://geodesic.mathdoc.fr/item/MZM_2002_72_2_a8/
[1] Semmes S., “Trace ideal criteria for Hankel operators and application to Besov space”, Integral Equations and Operator Theory, 7 (1984), 241–281 | DOI | MR | Zbl
[2] Peller V. V., “Operatory Gankelya klassa $\sigma_p$ i ikh prilozheniya (ratsionalnaya approksimatsiya, gaussovskie protsessy, problema mazhoratsii operatorov)”, Matem. sb., 113:4 (1980), 538–582 | MR
[3] Peller V. V., “Opisanie operatorov Gankelya klassa $\sigma_p$ pri $p>0$, issledovanie skorosti ratsionalnoi approksimatsii i drugie prilozheniya”, Matem. sb., 122:4 (1983), 481–510 | MR
[4] Rochberg R., “Decomposition theorems for Bergman spaces and their applications”, Operator and Functional Theory, Proc. NATO Adv. Study Inst. (Lancaster, July 16–24, 1984), D. Reidel Publ. Company, 1985, 225–277 | MR
[5] Pekarskii A. A., “Neravenstva tipa Bernshteina dlya proizvodnykh ratsionalnykh funktsii i obratnye teoremy ratsionalnoi approksimatsii”, Matem. sb., 124:4 (1984), 571–588 | MR | Zbl
[6] Garnett Dzh., Ogranichennye analiticheskie funktsii, Mir, M., 1984 | Zbl
[7] Lorentz G. G., Golitschek M. V., Makovoz Y., Constructive Approximation. Advanced Problems, Spinger-Verlag, Berlin, 1996