Document Type
Article
Department/Program
Mathematics
Journal Title
Canadian Mathematical Bulletin-Bulletin Canadien De Mathematiques
Pub Date
2016
Volume
59
Issue
2
First Page
354
Abstract
Let T be a quadratic operator on a complex Hilbert space H. We show that T can be written as a product of two positive contractions if and only if T is of the form aI circle plus bI circle plus [ GRAPHICS ] on H-1 circle plus H-2 circle plus (H-3 circle plus H-3) for some a, b is an element of [ 0, 1 ] and strictly positive operator P with parallel to P parallel to < = vertical bar root a - root b vertical bar root (1 - a) (1 - b). Also, we give a necessary condition for a bounded linear operator T with operator matrix [GRAPHICS] on H circle plus K that can be written as a product of two positive contractions.
Recommended Citation
Li, Chi-Kwong and Tsai, Ming-Cheng, Factoring a Quadratic Operator as a Product of Two Positive Contractions (2016). Canadian Mathematical Bulletin-Bulletin Canadien De Mathematiques, 59(2), 354-362.
10.4153/CMB-2015-049-4
DOI
10.4153/CMB-2015-049-4