Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4616027 | Journal of Mathematical Analysis and Applications | 2014 | 15 Pages |
Abstract
An n-dilation of a contraction T acting on a Hilbert space H is a unitary dilation acting on HâCn. We show that if both defect numbers of T are equal to n, then the closure of the numerical range of T is the intersection of the closures of the numerical ranges of its n-dilations. We also obtain detailed information about the geometrical properties of the numerical range of T in case n=1.
Keywords
Related Topics
Physical Sciences and Engineering
Mathematics
Analysis
Authors
Hari Bercovici, Dan Timotin,