On operators close to isometries
Volume 186 / 2008
Studia Mathematica 186 (2008), 275-293
MSC: Primary 47A16, 47B20.
DOI: 10.4064/sm186-3-6
Abstract
We introduce and discuss a class of operators, to be referred to as operators close to isometries. The Bergman-type operators, 2-hyperexpansions, expansive $p$-isometries, and certain alternating hyperexpansions are main examples of such operators. We establish a few decomposition theorems for operators close to isometries. Applications are given to the theory of $p$-isometries and of hyperexpansive operators.
