Abstract
Given Hilbert space operators A, B, C, one seeks an operator D such that $\| \left( \begin{array}{cc} A ~ C\\ B ~ D\end{array} \right) \| \leqq \mu$ for a pre-assigned bound $\mu$. In some contexts only the existence of D is called for; in others, one may want to know something about those D which work. This paper gives an exposition of the main theorems and of two of the many applications.
Information
Published: 1 January 1984
First available in Project Euclid: 18 November 2014
zbMATH: 0553.47004
MathSciNet: MR757564
Rights: Copyright © 1984, Centre for Mathematical Analysis, The Australian National University. This book is copyright. Apart from any fair dealing for the purpose of private study, research, criticism or review as permitted under the Copyright Act, no part may be reproduced by any process without permission. Inquiries should be made to the publisher.
