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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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
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author Zahra Orouji
Ali Ebadian
Nak Eun Cho
author_facet Zahra Orouji
Ali Ebadian
Nak Eun Cho
author_sort Zahra Orouji
collection DOAJ
description 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.
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spelling doaj.art-46147917fa644c76b4813cef0c4a92102023-11-30T21:12:12ZengMDPI AGAxioms2075-16802023-01-011219110.3390/axioms12010091On the Strong Starlikeness of the Bernardi TransformZahra Orouji0Ali Ebadian1Nak Eun Cho2Department of Mathematics, Faculty of Science, Urmia University, Urmia 5756151818, IranDepartment of Mathematics, Faculty of Science, Urmia University, Urmia 5756151818, IranDepartment of Applied Mathematics, College of Natural Sciences, Pukyong National University, Busan 608-737, Republic of KoreaMany 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.https://www.mdpi.com/2075-1680/12/1/91Nunokawa’s lemmaLibera operatorBernardi operatorstrongly starlike functions
spellingShingle Zahra Orouji
Ali Ebadian
Nak Eun Cho
On the Strong Starlikeness of the Bernardi Transform
Axioms
Nunokawa’s lemma
Libera operator
Bernardi operator
strongly starlike functions
title On the Strong Starlikeness of the Bernardi Transform
title_full On the Strong Starlikeness of the Bernardi Transform
title_fullStr On the Strong Starlikeness of the Bernardi Transform
title_full_unstemmed On the Strong Starlikeness of the Bernardi Transform
title_short On the Strong Starlikeness of the Bernardi Transform
title_sort on the strong starlikeness of the bernardi transform
topic Nunokawa’s lemma
Libera operator
Bernardi operator
strongly starlike functions
url https://www.mdpi.com/2075-1680/12/1/91
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