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Zapiski Nauchnykh Seminarov POMI, 2012, Volume 401, Pages 5–52
(Mi znsl5224)
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This article is cited in 6 scientific papers (total in 6 papers)
Operator Lipschitz functions and linear fractional transformations
A. B. Aleksandrov St. Petersburg Department of V. A. Steklov Institute of Mathematics, Russian Academy of Sciences, St. Petersburg, Russia
Abstract:
It is known that the function $t^2\sin\frac1t$ is an operator Lipschitz function on the real line $\mathbb R$. We prove that the function $\sin$ can be replaced by any operator Lipschitz function $f$ with $f(0)=0$. In other words, for every operator Lipschitz function $f$ the function $t^2 f(\frac1t)$ is also operator Lipschitz if $f(0)=0$. The function $f$ can be defined on an arbitrary closed subset of the complex plane $\mathbb C$. Moreover, the linear fractional transformation $\frac1t$ can be replaced by every linear fractional transformation $\varphi$. In this case, we assert that the function $\dfrac{f\circ\varphi}{\varphi'}$ is operator Lipschitz for every operator Lipschitz function $f$ provided $f(\varphi(\infty))=0$.
Key words and phrases:
operator Lipschitz functions.
Received: 23.04.2012
Citation:
A. B. Aleksandrov, “Operator Lipschitz functions and linear fractional transformations”, Investigations on linear operators and function theory. Part 40, Zap. Nauchn. Sem. POMI, 401, POMI, St. Petersburg, 2012, 5–52; J. Math. Sci. (N. Y.), 194:6 (2013), 603–627
Linking options:
https://www.mathnet.ru/eng/znsl5224 https://www.mathnet.ru/eng/znsl/v401/p5
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Abstract page: | 456 | Full-text PDF : | 115 | References: | 74 |
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