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arXiv · 1204.5134

Functions of perturbed tuples of self-adjoint operators

Fedor Nazarov·Vladimir Peller
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Abstract

We generalize earlier results of Peller, Aleksandrov - Peller, Aleksandrov - Peller - Potapov - Sukochev to the case of functions of $n$-tuples of commuting self-adjoint operators. In particular, we prove that if a function $f$ belongs to the Besov space $B_{\be,1}^1(\R^n)$, then $f$ is operator Lipschitz and we show that if $f$ satisfies a Hölder condition of order $\a$, then $\|f(A_1...,A_n)-f(B_1,...,B_n)\|\le\const\max_{1\le j\le n}\|A_j-B_j\|^\a$ for all $n$-tuples of commuting self-adjoint operators $(A_1,...,A_n)$ and $(B_1,...,B_n)$. We also consider the case of arbitrary moduli of continuity and the case when the operators $A_j-B_j$ belong to the Schatten--von Neumann class $\bS_p$.

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Fedor Nazarov, Vladimir Peller. 2012-04-23. Functions of perturbed tuples of self-adjoint operators. https://arxiv.org/abs/1204.5134

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