scholarly journals Best Subordinant for Differential Superordinations of Harmonic Complex-Valued Functions

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 2041
Author(s):  
Georgia Irina Oros
Keyword(s):  
Analytic Functions ◽  
Dual Problem ◽  
Differential Subordination ◽  
Research Subject ◽  
Harmonic Complex ◽  
Differential Superordination ◽  
Complex Valued ◽  
Differential Subordinations

The theory of differential subordinations has been extended from the analytic functions to the harmonic complex-valued functions in 2015. In a recent paper published in 2019, the authors have considered the dual problem of the differential subordination for the harmonic complex-valued functions and have defined the differential superordination for harmonic complex-valued functions. Finding the best subordinant of a differential superordination is among the main purposes in this research subject. In this article, conditions for a harmonic complex-valued function p to be the best subordinant of a differential superordination for harmonic complex-valued functions are given. Examples are also provided to show how the theoretical findings can be used and also to prove the connection with the results obtained in 2015.

scholarly journals Strong Differential Superordination Results Involving Extended Sălăgean and Ruscheweyh Operators

Mathematics ◽  
2021 ◽  
Vol 9 (19) ◽  
pp. 2487
Author(s):  
Alina Alb Lupaş ◽  
Georgia Oros
Keyword(s):  
Analytic Functions ◽  
Holomorphic Functions ◽  
Differential Subordination ◽  
New Approach ◽  
Ruscheweyh Derivative ◽  
Differential Superordination ◽  
Strong Differential Subordination ◽  
Extended Operator ◽  
Dual Notion ◽  
Differential Subordinations

The notion of strong differential subordination was introduced in 1994 and the theory related to it was developed in 2009. The dual notion of strong differential superordination was also introduced in 2009. In a paper published in 2012, the notion of strong differential subordination was given a new approach by defining new classes of analytic functions on U×U¯ having as coefficients holomorphic functions in U¯. Using those new classes, extended Sălăgean and Ruscheweyh operators were introduced and a new extended operator was defined as Lαm:Anζ*→Anζ*,Lαmf(z,ζ)=(1−α)Rmf(z,ζ)+αSmf(z,ζ),z∈U,ζ∈U¯, where Rmf(z,ζ) is the extended Ruscheweyh derivative, Smf(z,ζ) is the extended Sălăgean operator and Anζ*={f∈H(U×U¯), f(z,ζ)=z+an+1ζzn+1+⋯,z∈U,ζ∈U¯}. This operator was previously studied using the new approach on strong differential subordinations. In the present paper, the operator is studied by applying means of strong differential superordination theory using the same new classes of analytic functions on U×U¯. Several strong differential superordinations concerning the operator Lαm are established and the best subordinant is given for each strong differential superordination.

scholarly journals Fractional differential superordination

2014 ◽  
Vol 45 (3) ◽  
pp. 275-284
Author(s):  
Rabha W. Ibrahim
Keyword(s):  
Differential Operator ◽  
Unit Disk ◽  
Fractional Order ◽  
Analytic Functions ◽  
Dual Problem ◽  
Differential Subordination ◽  
Geometric Properties ◽  
Differential Superordination ◽  
Fractional Differential ◽  
Admissible Functions

The notion of differential superordination was introduced by S.S. Miller and P.T. Mocanu as a dual concept of differential subordination. Recently, in Tamkang J. Math.[7], the author have introduced the notion of fractional differential subordination. In this work, we consider the dual problem of determining properties of analytic functions that satisfy the fractional differential superordination. By employing some types of admissible functions, involving differential operator of fractional order, we illustrate geometric properties such as starlikeness and convexity for a class of analytic functions in the unit disk. Moreover, applications are posed in the sequel.

Sandwich results for analytic functions involving with iterations of the Owa–Srivastava operator and its combination

2014 ◽  
Vol 07 (04) ◽  
pp. 1450063
Author(s):  
Madan Mohan Soren
Keyword(s):  
Analytic Functions ◽  
Differential Subordination ◽  
Sandwich Type ◽  
Differential Superordination ◽  
Strong Differential Subordination

In this paper, we investigate some strong differential subordination and strong differential superordination results for analytic functions, which involving the iterations of the Owa–Srivastava operator and its combination. Some new sandwich type results are also obtained.

scholarly journals Applications of Differential Subordination for Argument Estimates of Multivalent Analytic Functions

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Meng-Ting Lu ◽  
Ting Jia ◽  
Xing-Qian Ling ◽  
Jin-Lin Liu
Keyword(s):  
Analytic Functions ◽  
Differential Subordination ◽  
Differential Subordinations

By using the method of differential subordinations, we derive some properties of multivalent analytic functions. All results presented here are sharp.

scholarly journals Differential Subordinations for Nonanalytic Functions

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Georgia Irina Oros ◽  
Gheorghe Oros
Keyword(s):  
Complex Plane ◽  
Classical Theory ◽  
Analytic Functions ◽  
Unit Disc ◽  
Sufficient Conditions ◽  
Differential Subordination ◽  
Analytic Case ◽  
Complex Functions ◽  
Differential Subordinations

In the paper by Mocanu (1980), Mocanu has obtained sufficient conditions for a function in the classesC1(U), respectively, andC2(U)to be univalent and to mapUonto a domain which is starlike (with respect to origin), respectively, and convex. Those conditions are similar to those in the analytic case. In the paper by Mocanu (1981), Mocanu has obtained sufficient conditions of univalency for complex functions in the classC1which are also similar to those in the analytic case. Having those papers as inspiration, we try to introduce the notion of subordination for nonanalytic functions of classesC1andC2following the classical theory of differential subordination for analytic functions introduced by Miller and Mocanu in their papers (1978 and 1981) and developed in their book (2000). LetΩbe any set in the complex planeC, letpbe a nonanalytic function in the unit discU,p∈C2(U),and letψ(r,s,t;z):C3×U→C. In this paper, we consider the problem of determining properties of the functionp, nonanalytic in the unit discU, such thatpsatisfies the differential subordinationψ(p(z),Dp(z),D2p(z)-Dp(z);z)⊂Ω⇒p(U)⊂Δ.

scholarly journals On a certain subclass of analytic functions defined by a generalized S˘al˘agean operator and Ruscheweyh derivative

2012 ◽  
Vol 28 (2) ◽  
pp. 183-190
Author(s):  
ALINA ALB LUPAS ◽  
Keyword(s):  
Analytic Functions ◽  
Unit Disc ◽  
Differential Subordination ◽  
Open Unit ◽  
Open Unit Disc ◽  
Ruscheweyh Derivative ◽  
Differential Subordinations

In the present paper we define a new operator using the generalized Sal˘ agean and Ruscheweyh operators. Denote by ˘ RDm λ,α the operator given by RDm λ,α : An → An, RDm λ,αf(z) = (1 − α)Rmf(z) + αDm λ f(z), z ∈ U, where Rmf(z) denote the Ruscheweyh derivative, Dm λ f(z) is the generalized Sal˘ agean operator and ˘ An = {f ∈ H(U) : f(z) = z +an+1z n+1 +. . . , z ∈ U} is the class of normalized analytic functions. A certain subclass, denoted by RDm (δ, λ, α) , of analytic functions in the open unit disc is introduced by means of the new operator. By making use of the concept of differential subordination we will derive various properties and characteristics of the class RDm (δ, λ, α) . Also, several differential subordinations are established regarding the operator RDm λ,α.

scholarly journals Some Properties for Strong Differential Subordination of Analytic Functions Involving Ruscheweyh Derivative Operator

2020 ◽  
pp. 63-70
Author(s):  
Asraa Abdul Jaleel Husien
Keyword(s):  
Unit Disk ◽  
Analytic Functions ◽  
Differential Subordination ◽  
Open Unit ◽  
Derivative Operator ◽  
Closed Unit Disk ◽  
Ruscheweyh Derivative Operator ◽  
Ruscheweyh Derivative ◽  
Strong Differential Subordination ◽  
Differential Subordinations

In this paper, we introduce and study some properties for strong differential subordinations of analytic functions associated with Ruscheweyh derivative operator defined in the open unit disk and closed unit disk of the complex plane.

scholarly journals On Special Differential Subordinations Using Fractional Integral of Sălăgean and Ruscheweyh Operators

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1553
Author(s):  
Alina Alb Lupaş ◽  
Georgia Irina Oros
Keyword(s):  
Analytic Functions ◽  
Unit Disc ◽  
Fractional Integral ◽  
Differential Subordination ◽  
Differential Subordinations

In the present paper, a new operator denoted by Dz−λLαn is defined by using the fractional integral of Sălăgean and Ruscheweyh operators. By means of the newly obtained operator, the subclass Snδ,α,λ of analytic functions in the unit disc is introduced, and various properties and characteristics of this class are derived by applying techniques specific to the differential subordination concept. By studying the operator Dz−λLαn, some interesting differential subordinations are also given.

scholarly journals Differential superordination for harmonic complex-valued functions

2019 ◽  
Vol 64 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Georgia Irina Oros ◽  
◽  
Gheorghe Oros ◽  
◽  
Keyword(s):  
Harmonic Complex ◽  
Differential Superordination ◽  
Complex Valued

scholarly journals Some Properties for Strong Differential Subordination of Analytic Functions Associated with Wanas Operator

2020 ◽  
pp. 29-38
Author(s):  
Abbas Kareem Wanas ◽  
Pall-Szabo Agnes Orsolya
Keyword(s):  
Unit Disk ◽  
Complex Plane ◽  
Analytic Functions ◽  
Differential Subordination ◽  
Open Unit ◽  
Open Unit Disk ◽  
Closed Unit Disk ◽  
Strong Differential Subordination ◽  
Differential Subordinations

In this paper, by making use of Wanas operator, we derive some properties related to the strong differential subordinations of analytic functions defined in the open unit disk and closed unit disk of the complex plane.

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