Higher derivatives of operator functions in ideals of von Neumann algebras
Abstract
Let be a von Neumann algebra and be a self-adjoint operator affiliated with . We define the notion of an "integral symmetrically normed ideal" of and introduce a space of functions such that the following result holds: for any integral symmetrically normed ideal of and any , the operator function is -times continuously Fr\'{e}chet differentiable, and the formula for its derivatives may be written in terms of multiple operator integrals. Moreover, we prove that if and is bounded, then . Finally, we prove that all of the following ideals are integral symmetrically normed: itself, separable symmetrically normed ideals, Schatten -ideals, the ideal of compact operators, and -- when is semifinite -- ideals induced by fully symmetric spaces of measurable operators.
Keywords
Cite
@article{arxiv.2107.03693,
title = {Higher derivatives of operator functions in ideals of von Neumann algebras},
author = {Evangelos A. Nikitopoulos},
journal= {arXiv preprint arXiv:2107.03693},
year = {2023}
}
Comments
43 pages. This version has been updated to match the published version, aside from the inclusion of a sketch of proof of Proposition 2.2.8 (omitted from the published version), the correction of some typos, and the adjustment of some references