Turkish Journal of Mathematics
DOI
-
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.
Keywords
Extreme points, hermitian elements
First Page
163
Last Page
170
Recommended Citation
HERZOG, GERD and SCHMOEGER, CHRISTOPH (2007) "Extreme Points of Certain Subsets of Hermitian Elements in Banach Algebras," Turkish Journal of Mathematics: Vol. 31: No. 2, Article 4. Available at: https://journals.tubitak.gov.tr/math/vol31/iss2/4
