GSMIS

Publication

Journal Publication

Title of Article

Bounds of the derivative of some classes of rational functions

Date of Acceptance

11 October 2021

Journal

Title of Journal

Thai Journal of Mathematics (TJM)

Standard

SCOPUS

Institute of Journal

Chiang Mai University

ISBN/ISSN

Volume

Issue

Month

Year of Publication

2021

Page

Abstract

Let r(z) be a rational function with at most n poles, a1, a2, . . . , an, where |aj | > 1, 1 ≤ j ≤ n. This paper investigates the estimate of the modulus of the derivative of a rational function r(z) on the unit circle. We establish an upper bound when all zeros of r(z) lie in |z| ≥ k ≥ 1 and a lower bound when all zeros of r(z) lie in |z| ≤ k ≤ 1. In particular, when k = 1 and r(z) has exactly n zeros, we obtain a generalization of results by Aziz and Shah.

Keyword

Blaschke product; derivative; inequality; maximum modulus; rational function

Author

617020041-9	Mr. NUTTAPONG ARUNRAT [Main Author]
	Science Doctoral Degree

Reviewing Status

มีผู้ประเมินอิสระ

Status

ได้รับการตอบรับให้ตีพิมพ์

Level of Publication

นานาชาติ

citation

true

Part of thesis

true

Attach file

Citation