Generation of subordinated holomorphic semigroups via Yosida's theorem

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Contribution

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Abstract

Using functional calculi theory, we obtain several estimates for $\|\psi(A)g(A)\|$, where $\psi$ is a Bernstein function, $g$ is a bounded completely monotone function and $-A$ is the generator of a holomorphic $C_0$-semigroup on a Banach space, bounded on $[0,\infty)$. Such estimates are of value, in particular, in approximation theory of operator semigroups. As a corollary, we obtain a new proof of the fact that $-\psi(A)$ generates a holomorphic semigroup whenever $-A$ does, established recently in [8] by a different approach.