scholarly journals Estimate for Schwarzian derivative of certain close-to-convex functions

2021 ◽  
Vol 6 (10) ◽  
pp. 10778-10788
Author(s):  
Zhenyong Hu ◽  
◽  
Xiaoyuan Wang ◽  
Jinhua Fan ◽  

<abstract><p>Let $ f(z) $ be analytic in the unit disk with $ f(0) = f'(0)-1 = 0 $. For the following close-to-convex subclasses: $ \Re \{(1-z)f'(z)\} &gt; 0, $ $ \Re \{(1-z^{2})f'(z)\} &gt; 0, $ $ \Re \{(1-z+z^{2})f'(z)\} &gt; 0 $ and $ \Re \{(1-z)^{2}f'(z)\} &gt; 0 $, we investigate the bounds for the first two consecutive derivatives of higher order Schwarzian derivatives of $ f(z) $.</p></abstract>

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Guangming Hu ◽  
Yutong Liu ◽  
Yu Sun ◽  
Xinjie Qian

Let S H f be the Schwarzian derivative of a univalent harmonic function f in the unit disk D , compatible with a finitely generated Fuchsian group G of the second kind. We show that if S H f 2 1 − z 2 3 d x d y satisfies the Carleson condition on the infinite boundary of the Dirichlet fundamental domain F of G , then S H f 2 1 − z 2 3 d x d y is a Carleson measure in D .


2010 ◽  
Vol 5 (3) ◽  
pp. 659-670 ◽  
Author(s):  
Seong-A Kim ◽  
Toshiyuki Sugawa

2006 ◽  
Vol 49 (1) ◽  
pp. 131-143 ◽  
Author(s):  
Yong Chan Kim ◽  
Toshiyuki Sugawa

AbstractA sharp norm estimate will be given to the pre-Schwarzian derivatives of close-to-convex functions of specified type. In order to show the sharpness, we introduce a kind of maximal operator which may be of independent interest. We also discuss a relation between the subclasses of close-to-convex functions and the Hardy spaces.


Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 348
Author(s):  
Nak Cho ◽  
Virendra Kumar ◽  
V. Ravichandran

Higher order Schwarzian derivatives for normalized univalent functions were first considered by Schippers, and those of convex functions were considered by Dorff and Szynal. In the present investigation, higher order Schwarzian derivatives for the Janowski star-like and convex functions are considered, and sharp bounds for the first three consecutive derivatives are investigated. The results obtained in this paper generalize several existing results in this direction.


2015 ◽  
Vol 08 (01) ◽  
pp. 1450024 ◽  
Author(s):  
Abbas Kareem Wanas

In this paper, we obtain some subordination and superordination results for higher-order derivatives of multivalent analytic functions in the open unit disk by generalized Noor integral operator. These results are applied to obtain sandwich results. Our results extend corresponding previously known results.


2014 ◽  
Vol 25 (10) ◽  
pp. 1450094
Author(s):  
Dorina Răducanu

In this paper, we consider a new class 𝒞(ϕ, ψ, η) of analytic functions defined by means of subordination. Coefficient bounds, Fekete–Szegö problem and norm estimates of the pre-Schwarzian derivatives of functions belonging to the class 𝒞(ϕ, ψ, η) are investigated. A class of multiple close-to-convex functions is also considered.


Filomat ◽  
2017 ◽  
Vol 31 (4) ◽  
pp. 1009-1016 ◽  
Author(s):  
Ahmet Akdemir ◽  
Özdemir Emin ◽  
Ardıç Avcı ◽  
Abdullatif Yalçın

In this paper, firstly we prove an integral identity that one can derive several new equalities for special selections of n from this identity: Secondly, we established more general integral inequalities for functions whose second derivatives of absolute values are GA-convex functions based on this equality.


Sign in / Sign up

Export Citation Format

Share Document