Isometries between C*-algebras

  • Cho-Ho J. Chu

    Queen Mary University, London, UK
  • Ngai-Ching Wong

    National Sun Yet-sen University, Kaohsiung, Taiwan


Let and be C*-algebras and let be a linear isometry from into . We show that there is a largest projection in such that is a Jordan triple homomorphism and

for all , , in . When is abelian, we have for all in . It follows that a (possibly non-surjective) linear isometry between any C*-algebras reduces locally to a Jordan triple isomorphism, by a projection.

Cite this article

Cho-Ho J. Chu, Ngai-Ching Wong, Isometries between C*-algebras. Rev. Mat. Iberoam. 20 (2004), no. 1, pp. 87–105

DOI 10.4171/RMI/381