Kyungpook Mathematical Journal

Department of Mathematics, Kyungpook National University (경북대학교 자연과학대학 수학과)
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Estimations of Zeros of a Polynomial Using Numerical Radius Inequalities

  • Bhunia, Pintu (Department of Mathematics, Jadavpur University) ;
  • Bag, Santanu (Department of Mathematics, Vivekananda College For Women) ;
  • Nayak, Raj Kumar (Department of Mathematics, Jadavpur University) ;
  • Paul, Kallol (Department of Mathematics, Jadavpur University)
  • Received : 2020.07.27
  • Accepted : 2021.02.24
  • Published : 2021.12.31
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Abstract

We present new bounds for the numerical radius of bounded linear operators and 2 × 2 operator matrices. We apply upper bounds for the numerical radius to the Frobenius companion matrix of a complex monic polynomial to obtain new estimations for the zeros of that polynomial. We also show with numerical examples that our new estimations improve on the existing estimations.

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Acknowledgement

The authors are grateful to the referee for his/her suggestions. First and third author would like to thank UGC, Govt. of India for the financial support in the form of JRF. Prof. Kallol Paul would like to thank RUSA 2.0, Jadavpur University for the partial support.

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