Certain Class of Meromorphically Multivalent Functions Associated with a Linear Operator

Author(s):  
Dr. Jitendra Awasthi

In this paper we have introduced a new subclass ( , , , , , ) ,, T a c A B p m l    of meromorphic p-valent functions in the punctured unit disk U*={z∈C:0 less than |z| less than 1} by sing a linear operator p m l I , , .Coefficients inequalities, Distortion theorems, Closure properties, Radii of starlikeness and convexity are obtained for this class. 2010 AMS CLASSIFICATION: Primary 30C45.

2003 ◽  
Vol 2003 (17) ◽  
pp. 1083-1091 ◽  
Author(s):  
J. A Kim ◽  
K. H. Shon

Forμ≥0, we consider a linear operatorLμ:A→Adefined by the convolutionfμ∗f, wherefμ=(1−μ)z2F1(a,b,c;z)+μz(z2F1(a,b,c;z))′. Letφ∗(A,B)denote the class of normalized functionsfwhich are analytic in the open unit disk and satisfy the conditionzf′/f≺(1+Az)/1+Bz,−1≤A<B≤1, and letRη(β)denote the class of normalized analytic functionsffor which there exits a numberη∈(−π/2,π/2)such thatRe(eiη(f′(z)−β))>0,(β<1). The main object of this paper is to establish the connection betweenRη(β)andφ∗(A,B)involving the operatorLμ(f). Furthermore, we treat the convolutionI=∫0z(fμ(t)/t)dt ∗f(z)forf∈Rη(β).


Author(s):  
O. P. Ahuja ◽  
H. Silverman

The convolution of two functionsf(z)=∑n=0∞anznandg(z)=∑n=0∞bnzndefined as(f∗g)(z)=∑n=0∞anbnzn. Forf(z)=z−∑n=2∞anznandg(z)=z/(1−z)2(1−γ), the extremal function for the class of functions starlike of orderγ, we investigate functionsh, whereh(z)=(f∗g)(z), which satisfy the inequality|(zh′/h)−1|/|(zh′/h)+(1-2α)|<β,0≤α<1,0<β≤1for allzin the unit disk. Such functionsfare said to beγ-prestarlike of orderαand typeβ. We characterize this family in terms of its coefficients, and then determine extreme points, distortion theorems, and radii of univalence, starlikeness, and convexity. All results are sharp.


2018 ◽  
Vol 7 (4.36) ◽  
pp. 806
Author(s):  
Amal Mohammed Darweesh

In this paper, we introduce and study a new subclass of meromorphic univalent functions with negative coefficients defined by Liu – Srivastava linear operator in the  We obtain some properties like, coefficients inequalities, growth and distortion theorems, closure theorems, partial sums and convolution properties.  


Symmetry ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 292 ◽  
Author(s):  
Hari Srivastava ◽  
Muhammad Tahir ◽  
Bilal Khan ◽  
Qazi Ahmad ◽  
Nazar Khan

By making use of the concept of basic (or q-) calculus, various families of q-extensions of starlike functions of order α in the open unit disk U were introduced and studied from many different viewpoints and perspectives. In this paper, we first investigate the relationship between various known classes of q-starlike functions that are associated with the Janowski functions. We then introduce and study a new subclass of q-starlike functions that involves the Janowski functions. We also derive several properties of such families of q-starlike functions with negative coefficients including (for example) distortion theorems.


2005 ◽  
Vol 2005 (4) ◽  
pp. 561-570 ◽  
Author(s):  
Rosihan M. Ali

A parabolic starlike functionfof orderρin the unit disk is characterized by the fact that the quantityzf′(z)/f(z)lies in a given parabolic region in the right half-plane. Denote the class of such functions byPS∗(ρ). This class is contained in the larger class of starlike functions of orderρ. Subordination results forPS∗(ρ)are established, which yield sharp growth, covering, and distortion theorems. Sharp bounds for the first four coefficients are also obtained. There exist different extremal functions for these coefficient problems. Additionally, we obtain a sharp estimate for the Fekete-Szegö coefficient functional and investigate convolution properties forPS∗(ρ).


Author(s):  
Zayid Abdulhadi

We consider logharmonic mappings of the formf(z)=z|z| 2βhg¯defined on the unit diskUwhich are typically real. We obtain representation theorems and distortion theorems. We determine the radius of univalence and starlikeness of these mappings. Moreover, we derive a geometric characterization of such mappings.


Filomat ◽  
2018 ◽  
Vol 32 (4) ◽  
pp. 1349-1357
Author(s):  
Grigore Sǎlǎgean ◽  
Páll-Szabó Orsolya

In this paper we investigate several classes of harmonic functions with varying argument of coefficients which are defined by means of the principle of subordination between harmonic functions. Properties such as the coefficient estimates, distortion theorems, convolution properties, radii of convexity, starlikeness and the closure properties of these classes under the generalized Bernardi-Libera-Livingston integral operators are investigated.


Author(s):  
Waggas Galib Atshan ◽  
Rajaa Ali Hiress

        By using of linear  operator, we obtain some Subordinations  and superordinations results for certain normalized meromorphic univalent analytic functions in the in the punctured open unit disk   Also we derive some sandwich theorems .


2002 ◽  
Vol 31 (11) ◽  
pp. 659-673 ◽  
Author(s):  
Nak Eun Cho ◽  
J. Patel ◽  
G. P. Mohapatra

The purpose of this paper is to derive some argument properties of certain multivalent functions in the open unit disk involving a linear operator. We also investigate their integral preserving property in a sector.


2020 ◽  
Vol 25 (2) ◽  
pp. 1-13 ◽  
Author(s):  
Waggas Galib Atshan ◽  
Ali Hussein Battor ◽  
Abeer Farhan Abaas ◽  
Georgia Irina Oros

In this paper, we introduce new concept that is fourth-order differential subordination and superordination associated with linear operator for univalent analytic functions in open unit disk. Here, we extended some lemmas. Also  some interesting new results are obtained.


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