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Refinements of some numerical radius inequalities for operators

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Abstract

In this work, we give several upper bounds for the numerical radius of the sum of two operators as well as for the numerical radii of \(2\times 2\) operator matrices. These upper bounds refine some earlier existing ones.

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Acknowledgements

The authors are grateful to the referee for his comments and suggestions.

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Authors and Affiliations

  1. Department of mathematics, Mustapha Stambouli University, Mascara, Algeria

    Soumia Aici & Abdelkader Frakis

  2. Department of mathematics, The university of Jordan, Amman, Jordan

    Fuad Kittaneh

Authors
  1. Soumia Aici
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  2. Abdelkader Frakis
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  3. Fuad Kittaneh
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Correspondence to Fuad Kittaneh.

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Aici, S., Frakis, A. & Kittaneh, F. Refinements of some numerical radius inequalities for operators. Rend. Circ. Mat. Palermo, II. Ser 72, 3815–3828 (2023). https://doi.org/10.1007/s12215-023-00864-w

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  • DOI: https://doi.org/10.1007/s12215-023-00864-w

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