Vector space isomorphisms of non-unital reduced Banach *-algebras

Rachid ElHarti, Mohamed Mabrouk

Abstract


Let A and B be two non-unital reduced Banach *-algebras and φ: A → B be a vector space isomorphism. The two following statement holds: If φ is a *-isomorphism, then φ is isometric (with respect to the C*-norms), bipositive and φ maps some approximate identity of A onto an approximate identity of B. Conversely, any two of the later three properties imply that φ is a *-isomorphism. Finally, we show that a unital and self-adjoint spectral isometry between semi-simple Hermitian Banach algebras is an *-isomorphism.

Keywords


Reduced Banach algebras; preserving the spectrum.

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References


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DOI: http://dx.doi.org/10.17951/a.2015.69.2.61-68
Date of publication: 2015-12-30 22:51:59
Date of submission: 2015-12-30 16:18:29


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