Abstract

We consider the real Banach spaces H(A) of all hermitian elements of a complex Banach algebra A. We prove that if an even power of a \in N(A) is hermitian, then a is an extreme point of the unit ball of H(A) if and only if a^2 = 1. Moreover, if an odd power of a \in H(A) is hermitian and a is an extreme point of the unit ball of H(A), then a^3 = a.

DOI

Keywords

Extreme points, hermitian elements

First Page

163

Last Page

170

Recommended Citation

HERZOG, G, & SCHMOEGER, C (2007). Extreme Points of Certain Subsets of Hermitian Elements in Banach Algebras. Turkish Journal of Mathematics 31 (2): 163-170. https://doi.org/-

Download