Extreme points of the closed unit ball in C*-algebras
Volume 74 / 1997
Colloquium Mathematicum 74 (1997), 99-100
DOI: 10.4064/cm-74-1-99-100
Abstract
In this short note we give a short and elementary proof of a characterization of those extreme points of the closed unit ball in C*-algebras which are unitary. The result was originally proved by G. K. Pedersen using some methods from the theory of approximation by invertible elements.
