On Wold-type decomposition
A new necessary and sufficient condition for a Hilbert space contraction to have \(C_{.0}\) completely nonunitary (cnu) part (in the sense of Sz.-Nagy and Foiaş) is given. This result is used to show that the cnu part of several generalizations of hyponormal contractions is of class \(C_{.0}\).
scientific article; zbMATH DE number 6034436