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This article is cited in 15 scientific papers (total in 15 papers)
Inverse theorems on generalized Padé approximants
S. P. Suetin
Abstract:
In this paper the following theorem is proved.
Theorem. {\it For $m>0$ and all sufficiently large $n$, let the Padé approximants $R_{n,m}$ of the series
$$
f(z)=\sum_{\nu=0}^\infty A_\nu F_\nu(z),\qquad A_\nu=(f,F_\nu)=\int_{-1}^1f(x)F_\nu(x)\,d\alpha(x),
$$
have exactly $m$ finite poles, and let there exist a polynomial $\omega_m(z)=\prod_{j=1}^m(z-z_j)$ such that
$$
\varlimsup_{n\to\infty}\|q_{n,m}-\omega_m\|^{1/n}\leqslant\delta<1.
$$
Then
$$
\rho_m(f)\geqslant\frac1\delta\max_{1\leqslant j\leqslant m}|\varphi(z_j)|
$$
and in the region $D_m(f)=D_{\rho_m}$ the function $f$ has exactly $m$ poles (at the points $z_1,\dots,z_m$).
}
Bibliography: 8 titles.
Received: 20.10.1978
Citation:
S. P. Suetin, “Inverse theorems on generalized Padé approximants”, Math. USSR-Sb., 37:4 (1980), 581–597
Linking options:
https://www.mathnet.ru/eng/sm2413https://doi.org/10.1070/SM1980v037n04ABEH002096 https://www.mathnet.ru/eng/sm/v151/i4/p629
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Abstract page: | 368 | Russian version PDF: | 101 | English version PDF: | 6 | References: | 49 | First page: | 2 |
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