On the Strong Starlikeness of the Bernardi Transform

Many papers concern both the starlikeness and the convexity of Bernardi integral operator. Using the Nunokawa’s Lemma, we want to determine conditions for the strong starlikeness of the Bernardi transform of normalized analytic functions <i>g</i>, such that <inline-formula><math...

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Bibliographic Details
Main Authors: Zahra Orouji, Ali Ebadian, Nak Eun Cho
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Axioms
Subjects:
Online Access:https://www.mdpi.com/2075-1680/12/1/91
Description
Summary:Many papers concern both the starlikeness and the convexity of Bernardi integral operator. Using the Nunokawa’s Lemma, we want to determine conditions for the strong starlikeness of the Bernardi transform of normalized analytic functions <i>g</i>, such that <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>|</mo><mo form="prefix">arg</mo></mrow><mrow><mo>{</mo><msup><mi>g</mi><mo>′</mo></msup><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow><mo>}</mo></mrow><mrow><mo>|</mo><mo> </mo><mo><</mo></mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><mi>α</mi><mi>π</mi></mrow><mn>2</mn></mfrac></mstyle></mrow></semantics></math></inline-formula> in the open unit disk <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Δ</mo></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo><</mo><mi>α</mi><mo><</mo><mn>2</mn></mrow></semantics></math></inline-formula>. Our results include the results of Mocanu, Nunokawa and others on the Libera transform.
ISSN:2075-1680