• Maps preserving $A^{\ast} A + AA^{\ast}$ on $C^{\ast}$-algebras

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      https://www.ias.ac.in/article/fulltext/pmsc/129/03/0030

    • Keywords

       

      $C^{*}$-algebra; $\mathbb{C}$-linear; $\mathbb{C}$-antilinear; homomorphism; linear preserver problem; real rank zero

    • Abstract

       

      Let $\mathcal{A}$ be a $C^{*}$-algebra of real-rank zero and $\mathcal{B}$ be a $C^{*}$-algebra with unit $I$. It is shown that the mapping $\Phi: {\mathcal A}\longrightarrow {\mathcal B}$ which preserves arithmetic mean and satisfies$$\Phi(A^{*}A)=\frac{\Phi(A)^{*}\Phi(A)+\Phi(A)\Phi(A)^{*}}{2},$$for all normal elements $A\in \mathcal{A}$, is an $\mathbb R$-linear continuous Jordan $*$-homomorphism provided that $0\in {\rm Ran}\ \Phi$. Also, $\Phi$ is the sum of a linear Jordan $*$-homomorphism and a conjugate-linear Jordan $*$-homomorphism. This result also presents an application of maps which preserve the square absolute value.

    • Author Affiliations

       

      ALI TAGHAVI1

      1. Department of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, P. O. Box 47416-1468, Babolsar, Iran
    • Dates

       
  • Proceedings – Mathematical Sciences | News

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