Notes on $q$-deformed operators
Volume 165 / 2004
Studia Mathematica 165 (2004), 295-301
MSC: 47A05, 47A10, 47B25.
DOI: 10.4064/sm165-3-7
Abstract
The paper concerns operators of deformed structure like $q$-normal and $q$-hyponormal operators with the deformation parameter $q$ being a positive number different from $1$. In particular, an example of a $q$-hyponormal operator with empty spectrum is given, and $q$-hyponormality is characterized in terms of some operator inequalities.
