Measures of noncompactness in Hilbert $C^*$-modules
Operator Algebras
2024-09-05 v1 Functional Analysis
Abstract
Consider a countably generated Hilbert -module over a -algebra . There is a measure of noncompactness defined, roughly as the distance from finitely generated projective submodules, which is independent of any topology. We compare to the Hausdorff measure of noncompactness with respect to the family of seminorms that induce a topology recently iontroduced by Troitsky, denoted by . We obtain . Related inequalities involving other known measures of noncompactness, e.g. Kuratowski and Istr\u{a}\c{t}escu are laso obtained as well as some related results on adjontable operators.
Keywords
Cite
@article{arxiv.2409.02514,
title = {Measures of noncompactness in Hilbert $C^*$-modules},
author = {Dragoljub J. Kečkić and Zlatko Lazović},
journal= {arXiv preprint arXiv:2409.02514},
year = {2024}
}
Comments
14 pages