Acta mathematica scientia,Series A ›› 2016, Vol. 36 ›› Issue (3): 413-424.

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Maps Preserving Partial Isometries of Operator Pencils

Wei Yanan, Ji Guoxing   

  1. College of Mathematics and Information Science, Shaanxi Normal University, Xi'an 710119
  • Received:2015-11-16 Revised:2016-04-12 Online:2016-06-26 Published:2016-06-26
  • Supported by:

    Supported by the NSFC (11371233) and the Fundamental Research Funds for the Central Universities (GK201301007)

Abstract:

Let B(H) be the algebra of all bounded linear operators on a complex Hilbert space H, PI(H) the set of all partial isometries in B(H). It is proved that a surjective map Φ on B(H) preserves partial isometries of pencils of operators, that is, ABPI(H)⇔Φ(A)-λΦ(B)∈PI(H) if and only if there are two unitary operators U and V on H such that Φ(X)=UXV for all X in B(H) or there are two anti-unitary operators U and V on H such that Φ(X)=UX*V for all X in B(H).

Key words: Partial isometry, Partial ordering, Surjective map, Operator pencil

CLC Number: 

  • O177.1
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