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  • Research Article
  • Open Access

Extensions of the results on powers of -hyponormal and -hyponormal operators

Journal of Inequalities and Applications20062006:36919

https://doi.org/10.1155/JIA/2006/36919

  • Received: 22 November 2004
  • Accepted: 10 May 2005
  • Published:

Abstract

Firstly, we will show the following extension of the results on powers of -hyponormal and -hyponormal operators: let and be positive integers, if is -hyponormal for , then: (i) in case , and hold, (ii) in case , and hold. Secondly, we will show an estimation on powers of -hyponormal operators for which implies the best possibility of our results. Lastly, we will show a parallel estimation on powers of -hyponormal operators as follows: let , then the following hold for each positive integer and : (i) there exists a log-hyponormal operator such that , (ii) there exists a -hyponormal operator such that .

Keywords

  • Positive Integer
  • Parallel Estimation
  • Good Possibility
  • Hyponormal Operator

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Authors’ Affiliations

(1)
College of Mathematics and Information Science, Henan Normal University, Xinxiang, 453007, China

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