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Generalizations of Reid inequality

  • Souheyb Dehimi and Mohammed Hichem Mortad EMAIL logo
Published/Copyright: November 20, 2018
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Abstract

In this paper, we improve the famous Reid inequality related to linear operators. Some monotony results for positive operators are also established with a different approach from what is known in the existing literature. Lastly, Reid’s (and Halmos-Reid’s) inequalities are extended to unbounded operators.



  1. (Communicated by Werner Timmermann)

Acknowledgement

We warmly thank Professor J. Stochel for communicating Lemma 2.4 to the corresponding author.

We also thank the anonymous referees for all their suggestions and valuable remarks.

References

[1] Dehimi, S.—Mortad, M. H.: Right (or left) invertibility of bounded and unbounded operators and applications to the spectrum of products, Complex Anal. Oper. Theory 12(3) (2018), 589–597. 10.1007/s11785-017-0687-z.Search in Google Scholar

[2] Halmos, P. R.: A Hilbert Space Problem Book, D. Van Nostrand Co., Inc., Princeton, N.J.-Toronto, Ont.-London, 1967.Search in Google Scholar

[3] Kato, T.: Perturbation Theory for Linear Operators, 2nd edition, Springer, 1980.Search in Google Scholar

[4] Kittaneh, F.: Notes on some inequalities for Hilbert space operators, Publ. Res. Inst. Math. Sci. 24(2) (1988), 283–293.10.2977/prims/1195175202Search in Google Scholar

[5] Lin, C.-S.: Inequalities of Reid type and Furuta, Proc. Amer. Math. Soc. 129(3) (2001), 855–859.10.1090/S0002-9939-00-05650-1Search in Google Scholar

[6] Lin, C.-S.—Dragomir, S. S.: On high-power operator inequalities and spectral radii of operators, Publ. Res. Inst. Math. Sci. 42(2) (2006), 391–397.10.2977/prims/1166642108Search in Google Scholar

[7] Mortad, M. H.: An improvement of Reid inequality, arXiv:1704.05104v1.Search in Google Scholar

[8] Reid, W. T.: Symmetrizable completely continuous linear transformations in Hilbert space, Duke Math. J. 18 (1951), 41–56.10.1215/S0012-7094-51-01805-4Search in Google Scholar

[9] Schmüdgen, K.: Unbounded Self-Adjoint Operators on Hilbert Space. Springer GTM 265, 2012.10.1007/978-94-007-4753-1Search in Google Scholar

[10] Young, N.: An Introduction to Hilbert Space. Cambridge Mathematical Textbooks, Cambridge University Press, Cambridge, 1988.Search in Google Scholar

Received: 2017-09-23
Accepted: 2017-12-15
Published Online: 2018-11-20
Published in Print: 2018-12-19

© 2018 Mathematical Institute Slovak Academy of Sciences

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