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arXiv · 1411.1815

Functions of perturbed noncommuting self-adjoint operators

Aleksei Aleksandrov·Fedor Nazarov·Vladimir Peller
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Abstract

We consider functions $f(A,B)$ of noncommuting self-adjoint operators $A$ and $B$ that can be defined in terms of double operator integrals. We prove that if $f$ belongs to the Besov class $B_{\be,1}^1(\R^2)$, then we have the following Lipschitz type estimate in the trace norm: $\|f(A_1,B_1)-f(A_2,B_2)\|_{\bS_1}\le\const(\|A_1-A_2\|_{\bS_1}+\|B_1-B_2\|_{\bS_1})$. However, the condition $f\in B_{\be,1}^1(\R^2)$ does not imply the Lipschitz type estimate in the operator norm.

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Aleksei Aleksandrov, Fedor Nazarov, Vladimir Peller. 2014-11-07. Functions of perturbed noncommuting self-adjoint operators. https://arxiv.org/abs/1411.1815

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