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This article is cited in 2 scientific papers (total in 2 papers)
An estimate of approximation of a matrix-valued function by an interpolation polynomial
V. G. Kurbatov, I. V. Kurbatova Voronezh State University,
1 Universitetskaya Square,
394018 Voronezh, Russia
Abstract:
Let $A$ be a square complex matrix; $z_1,\dots,z_n\in\mathbb{C}$ be (possibly repetitive) points of
interpolation; $f$ be a function analytic in a neighborhood of the convex hull of the union of the
spectrum of $A$ and the points $z_1,\dots,z_n$; and $p$ be the interpolation polynomial of $f$ constructed by
the points $z_1,\dots,z_n$. It is proved that under these assumptions
$$
||f(A)-p(A)||\leqslant \frac1{n!}\max_{t\in[0,1]\atop {\mu\in co\{z_1,z_2,\dots,z_n\}}}||\Omega(A)f^{(n)}((1-t)\mu\mathbf{1}+tA)||,
$$
where $\Omega(z)=\prod_{k=1}^n(z-z_k)$ and the symbol $co$ means the convex hull.
Keywords and phrases:
matrix function, polynomial interpolation, estimate.
Received: 18.03.2019
Citation:
V. G. Kurbatov, I. V. Kurbatova, “An estimate of approximation of a matrix-valued function by an interpolation polynomial”, Eurasian Math. J., 11:1 (2020), 86–94
Linking options:
https://www.mathnet.ru/eng/emj358 https://www.mathnet.ru/eng/emj/v11/i1/p86
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Abstract page: | 447 | Full-text PDF : | 141 | References: | 46 |
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