English

A characterisation of C*-algebras through positivity of functionals

Operator Algebras 2023-05-31 v2 Functional Analysis

Abstract

We show that a unital involutive Banach algebra, with identity of norm one and continuous involution, is a C*-algebra, with the given involution and norm, if every continuous linear functional attaining its norm at the identity is positive.

Keywords

Cite

@article{arxiv.1205.6830,
  title  = {A characterisation of C*-algebras through positivity of functionals},
  author = {Marcel de Jeu and Jun Tomiyama},
  journal= {arXiv preprint arXiv:1205.6830},
  year   = {2023}
}

Comments

3 pages. Some typos corrected. Final version, to appear in Ann. Funct. Anal