Essentially Commuting with a Unitary
Functional Analysis
2025-01-08 v1 Mathematical Physics
math.MP
Operator Algebras
Abstract
Let be a unitary operator whose spectrum is the circle. We show that the set of unitaries which essentially commute with (i.e., is compact) is path-connected. Moreover, we also calculate the set of path-connected components of the orthogonal projections which essentially commute with and obey a non-triviality condition, and prove it is bijective with .
Cite
@article{arxiv.2501.03934,
title = {Essentially Commuting with a Unitary},
author = {Jui-Hui Chung and Jacob Shapiro},
journal= {arXiv preprint arXiv:2501.03934},
year = {2025}
}