Multiple operator integrals in non-separable von Neumann algebras
Abstract
A multiple operator integral (MOI) is an indispensable tool in several branches of noncommutative analysis. However, there are substantial technical issues with the existing literature on the "separation of variables" approach to defining MOIs, especially when the underlying Hilbert spaces are not separable. In this paper, we provide a detailed development of this approach in a very general setting that resolves existing technical issues. Along the way, we characterize several kinds of "weak" operator valued integrals in terms of easily checkable conditions and prove a useful Minkowski-type integral inequality for maps with values in a semifinite von Neumann algebra.
Cite
@article{arxiv.2107.03687,
title = {Multiple operator integrals in non-separable von Neumann algebras},
author = {Evangelos A. Nikitopoulos},
journal= {arXiv preprint arXiv:2107.03687},
year = {2023}
}
Comments
48 pages. This version has been updated to match the published version, aside from the inclusion of proofs of Proposition 3.1.2, Proposition 3.2.5, and Lemma 3.4.2 (omitted from the published version); the correction of some typos; and the adjustment of some references