Estimates for the polar derivative of a constrained polynomial on a disk
Author
Milovanović, Gradimir V.
Mir, Abdullah
Hussain, Adil
Full text
https://revistas.ufro.cl/ojs/index.php/cubo/article/view/321410.56754/0719-0646.2403.0541
Abstract
This work is a part of a recent wave of studies on inequalities which relate the uniform-norm of a univariate complex coefficient polynomial to its derivative on the unit disk in the plane. When there is a limit on the zeros of a polynomial, we develop some additional inequalities that relate the uniform-norm of the polynomial to its polar derivative. The obtained results support some recently established Erdős-Lax and Turán-type inequalities for constrained polynomials, as well as produce a number of inequalities that are sharper than those previously known in a very large literature on this subject.