Numerical Ranges of Operators on Normed Spaces and of Elements of Normed Algebras

London Mathematical Society Lecture Note #2

by F.F. Bonsall, J. Duncan

The theory of the numerical range of a linear operator on an arbitrary normed space had its beginnings around 1960, and during the 1970s the subject has developed and expanded rapidly. This book presents a self-contained exposition of the subject as a whole. The authors develop various applications, in particular to the study of Banach algebras where the numerical range provides an important link between the algebraic and metric structures.

148 pages, Paperback

First published March 2, 1971