• Title/Summary/Keyword: standard operator algebras

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ADDITIVITY OF LIE MAPS ON OPERATOR ALGEBRAS

  • Qian, Jia;Li, Pengtong
    • Bulletin of the Korean Mathematical Society
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    • v.44 no.2
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    • pp.271-279
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    • 2007
  • Let A standard operator algebra which does not contain the identity operator, acting on a Hilbert space of dimension greater than one. If ${\Phi}$ is a bijective Lie map from A onto an arbitrary algebra, that is $${\phi}$$(AB-BA)=$${\phi}(A){\phi}(B)-{\phi}(B){\phi}(A)$$ for all A, B${\in}$A, then ${\phi}$ is additive. Also, if A contains the identity operator, then there exists a bijective Lie map of A which is not additive.

MAPS PRESERVING SOME MULTIPLICATIVE STRUCTURES ON STANDARD JORDAN OPERATOR ALGEBRAS

  • Ghorbanipour, Somaye;Hejazian, Shirin
    • Journal of the Korean Mathematical Society
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    • v.54 no.2
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    • pp.563-574
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    • 2017
  • Let $\mathcal{A}$ be a unital real standard Jordan operator algebra acting on a Hilbert space H of dimension at least 2. We show that every bijection ${\phi}$ on $\mathcal{A}$ satisfying ${\phi}(A^2{\circ}B)={\phi}(A)^2{\circ}{\phi}(B)$ is of the form ${\phi}={\varepsilon}{\psi}$ where ${\psi}$ is an automorphism on $\mathcal{A}$ and ${\varepsilon}{\in}\{-1,1\}$. As a consequence if $\mathcal{A}$ is the real algebra of all self-adjoint operators on a Hilbert space H, then there exists a unitary or conjugate unitary operator U on H such that ${\phi}(A)={\varepsilon}UAU^*$ for all $A{\in}\mathcal{A}$.