Uniqueness condition for the Pick problem.
Unitary asymptotes of Hilbert space operators
In this survey article we are going to present the effectiveness of the use of unitary asymptotes in the study of Hilbert space operators.
Unitary equivalence of operators and dilations
Given two contractions T and T' such that T'-T is an operator of finite rank, we prove, under some conditions, the unitary equivalence of the unitary parts of the minimal isometric dilations (respectively minimal co-isometric extensions) of T and T'.