Note on Wermuth's theorem on commuting operator exponentials
Functional Analysis
2025-04-09 v2 Operator Algebras
Rings and Algebras
Abstract
We apply Wermuth's theorem on commuting operator exponentials to show that if , being Banach space and of -congruence free spectrum, then if and only if . We employ this observation to provide alternative proof of similar result by Chaban and Mortad, applicable for being a Hilbert space.
Cite
@article{arxiv.1901.10261,
title = {Note on Wermuth's theorem on commuting operator exponentials},
author = {Krzysztof Szczygielski},
journal= {arXiv preprint arXiv:1901.10261},
year = {2025}
}
Comments
4 pages, no figures. Results largely incorporated into arXiv:2504.01176