Estimations of zeros of a polynomial using numerical radius inequalities

Pintu Bhunia, Santanu Bag, Raj Kumar Nayak, Kallol Paul

Published 2020-01-27Version 1

We present new bounds for the numerical radius of bounded linear operators and $2\times 2$ 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 zeros of that polynomial. We also show with numerical examples that our new estimations improve on the existing estimations.