Chinese Quarterly Journal of Mathematics ›› 2012, Vol. 27 ›› Issue (3): 375-381.

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The Properties of k-quasi-∗-A(n) Operator

  

  1. 1. College of Mathematics and Information Science, Henan Normal University 2. Department of Mathematics, Xinxiang University

  • Received:2010-11-11 Online:2012-09-30 Published:2023-03-23
  • About author:ZUO Fei(1978-), male, native of Dengzhou, Henan, a lecturer of Henan Normal University, engages in operator theory.
  • Supported by:
    Supported by the Natural Science Foundation of the Department of Education of Henan Province(12B110025,102300410012)

Abstract: An operator T is called k-quasi-*-A(n) operator, if T*k|T1+n|2/(1+n)Tk≥T*k|T*|2Tk, k ∈ Z, which is a generalization of quasi-*-A(n) operator. In this paper we prove some properties of k-quasi-*-A(n) operator, such as, if T is a k-quasi-*-A(n) operator and N(T )N(T*), then its point spectrum and joint point spectrum are identical. Using these results, we also prove that if T is a k-quasi-*-A(n) operator and N(T )N(T*), then the spectral mapping theorem holds for the Weyl spectrum and for the essential approximate point spectrum. 

Key words: k-quasi-?-A(n) operator, quasisimilarity, single valued extension property; Weyl spectrum, essential approximate point spectrum

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