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Research Article

Study analytical function subordination properties by applying a novel linear operator

[version 1; peer review: awaiting peer review]
PUBLISHED 31 Dec 2025
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This article is included in the Fallujah Multidisciplinary Science and Innovation gateway.

Abstract

Background

The study of theory for analytic univalent and multivalent functions is an old subject in mathematics, particularly in complex analysis, that has captivated a great deal of scholars owing to the sheer sophistication of its geometrical features as well as its many research possibilities. The study of univalent functions is one of many significant elements of complex analysis for both single and multiple variables. Investigators have become keen on the conventional investigation of this topic since at least 1907. Numerous scholars in the area of complex analysis have emerged since then, including Euler, Gauss, Riemann, Cauchy, and other people. Geometric function theory combines geometry and analysis.

Methods

This study employs the differential subordination technique to derive multiple characteristics from the new linear operator M σ , μ n , ς Υ ( s ) . The concept of the differential subordination subclass of analytical univalent functions is analyzed.

Results

In this section, We studied some results on differential subordination and superordination using a specific class of univalent functions stated on a specific space of univalent functions stated on the open unit disc. Using properties of the operator, we discovered a number of properties of superordinations and subordinations related to the idea of the Hadamard product. We investigated several aspects of superordinations and subordinations using a new operator M σ , μ n , ς Υ ( s ) .

Conclusions

A new operator M σ , μ n , ς Υ ( s ) : Λ ⟶ Λ has been established in this paper connected to the Dziok-Srivastava operator T σ n and the Hadamard product corresponding to the Komatu integral operator Ω μ ς . The difference operator M σ , μ n , ς ϒ ( s ) can have specific properties derived by applying the differential subordination technique. And the objective of this paper is to make use of the connection ( β 1 μ + 1 ) M σ , μ n + 1 , ς ϒ ( s ) = w ( M σ , μ n , ς ϒ ( s ) ) ′ + β 1 μ ( M σ , μ n , ς ϒ ( s ) ) .

Keywords

Univalent Function, Best Dominant, Derivative Operator, Differential Subordination, Convex Function, Hadamard Product.

1. Introduction

Gronwall’s Area Theorem, published in 1914, was a significant contribution to the theory of univalent functions. It is used for getting bounds on the coefficient values for meromorphic functions. Bieberbach resolved a similar issue regarding the class in 1916, as well as his known conjecture, which was mentioned in the exact same year but not applied until 1984, influenced the development of different methods in the geometric theory of complex variable functions. Estimates on the first two Taylor-Maclaurin coefficients are common in the study of bi-univalent functions since they are in the classes investigated by Gronwall and Bieberbach. Littlewood1 is the source of the fundamental findings on subordination that Rogosinski2 created and established. Subordination was recently utilized by Srivastava and Owa3 to investigate the fascinating properties of the generalized hypergeometric function. A paper on differential subordinations, a generalization of differential disparities, was written by Miller and Mocanu.4 The article is mainly concerned with the differential superordination of univalent functions in an open unit disk. To determine subordination properties, utilize the capabilities of the recently introduced operator Mσ,μn,ςϒ(s) . Miller as well as Mocanu created the differential subordinations method in 1978, and the theory started to take shape in 1981. Refer to59 for further information. Suppose Λ indicates the type of functions of the given form

(1)
ϒ(s)=s+η=2eηsη,eη0,
is analytic function in unit disk Δ={s:s,|s|<1} . Allow ϕ in Λ be provided by
(2)
ϕ(s)=s+η=2dηsη,dη0.

The following is the Hadamard product of ϒ and ϕ :

(3)
(ϒϕ)(s)=z+η=2eηdηsη,eηdη0.

When ϒ and ϕ are analytic in Δ, the function ϒ is considered subservient to ϕ, expressed as

ϒ(s)ϕ(s)(sΔ).

The previously Schwarz function ω is present in Δ if and only if |w(ω)|<1 as well as ω(0)=0 , if and only if there exists the Schwarz function ω , in Δ , with ω(0)=0 and |w(ω)|<1 such that

ϒ(s)=ϕ(ω(s)),(sΔ).

Additionally, we’re left with the following equivalency if ϕ is univalent in Δ by,1013: ϒϕ if and only if ϒ(0)=ϕ(0) and ϒ(Δ)ϕ(Δ).

2. Definitions and Lemmas

Definition 2.1.

14 The definition of the Komatu Integral operator Ωμς:ΛΛ for ϒΛ is

(4)
Ωμς(s)=s+η=2(μ+η1μ)ςsn,(μ>0;ς0).

Definition 2.2.

15 The definition of the Dziok-Srivastava operator Ωμς:ΛΛ for ϒΛ is

(5)
Tσn(β1,β2,..,βn;π1,π2..,πσ)ϒ(s)=s+η=2(β1)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(μ+η1μ)eηsη,
where βn,n=1,2,3,,n,πn{0,1,2,..},n=1,2,..,σ.

Definition 2.3.

If a function ϒ(s)Λ and Hadamard products between operator Tσn as well as operator Ωμς given a new linear operator Mσ,μn,ςϒ(s):ΛΛ , define

(6)
Mσ,μn,ςϒ(s)=Tσnϒ(s)Ωμς(s),(sΔ),andMσ,μn,ςϒ(s)=s+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsη.

Form Eq. 6, we have

(7)
(β1μ+1)Mσ,μn+1,ςϒ(s)=w(Mσ,μn,ςϒ(s))+β1μ(Mσ,μn,ςϒ(s)),(sΔ)

It should be noted that Mσ,μn,ςϒ has the following special cases.

  • a) The Komatu Integral operator Ωμς should be included if n=1,σ=1 by.14

  • b) Add the Dziok-Srivastava operator Tσn if ς=0 15,16

  • c) Salagean17 examined the case if μ=1,ς=n,n=1,σ=1 .

  • d) It was examined by Salagean17 and Flett18 if μ=1,ς=n,n=1,σ=1 .

Definition 2.4.

If σ,0π<1,μ>0;n,ς0, then let Rσ,μn,ς(π) denote the class of a function ϒΛ that satisfies the given conditions.

(8)
R(Mσ,μn,ςϒ(s))>π,(sΔ).

Lemma 2.1.

19 Assume that ϒ is in Λ, if R(1+sϒ(s)ϒ(s))>12, then

2s0sϒ(τ),(sΔands0),
is a convex functions.

Lemma 2.2.

20 Let ϕ be a convex function in Δ such that

ψ(s)=ϕ(s)+ηβsϕ(s),(sΔ), in which β>0 and η. If ϖ(s)=ϕ(0)+ϖηsη+ϖη+1sη+1+, is analytic in Δ and ϖ(s)+βsϖ(s)ψ(s) , then

ϖ(s)ϕ(s).

Lemma 2.3.

19 Consider the following ψ(0)=e , ξ is analytic, univalent, and convex in Δ, γ{0} is a complex number that produces R{γ}0. Given ϖΗ[e,η] as well as ϖ(s)+sϖ(s)γψ(s), then

ϖ(s)ξ(s)ψ(s),(sΔ),whereξ(s)=γηsγη0sψ(τ)τγη1,(sΔ).

The optimal prevailing of the subordination is the convex function ξ .

3. Results and Discussion

In this study, we will derive multiple characteristics derived from the new linear operator Mσ,μn,ςϒ(s) using differential subordination technique.

Theorem 3.1.

Let ψ(0)=1,0π<1 and ψ(s)=1+(2π1)s1+s be convex in Δ . Suits the differential subordination (Mσ,μn+1,ςϒ(s))ψ(s) for σ,μ>0;n,ς0 as well as ϒA , then

(9)
(Mσ,μn,ςϒ(s))ξ(s)=(32π1)+3/2(β1μ+1)(1π)ηs(β1μ+1)/ηζ((β1μ+1)/η),
where
ζ(x)=0sτx11+τ,(sΔ).

Proof.

The result of differentiation Eq. (7) is

(10)
(β1μ+1)(Mσ,μn+1,ςϒ(s))=(β1μ+1)(Mσ,μn,ςϒ(s))+s(Mσ,μn,ςϒ(s))(Mσ,μn+1,ςϒ(s))=(β1μ+1)(Mσ,μn,ςϒ(s))+s(Mσ,μn,ςϒ(s))(β1μ+1)(Mσ,μn+1,ςϒ(s))=(Mσ,μn,ςϒ(s))+s(Mσ,μn,ςϒ(s))(β1μ+1).

When Eq. (10) is used in Eq. (9), the subordination Eq. (9) is transformed into

(11)
(Mσ,μn,ςϒ(s))+s(Mσ,μn,ςϒ(s))(β1μ+1)ψ(s)=1+(32π1)1+s.

Let

(12)
ϖ(s)=(Mσ,μn,ςϒ(s))=(s+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsη),ϖ(s)=1+ϖ1s+ϖ2s2+,ϖΗ[1,1],sΔ.

Subordination is made possible in Eq. (11), through the use of Eq. (12).

ϖ(s)+sϖ(s)(β1μ+1)ψ(s)=1+(3/2π1)1+s.

Employing Lemma 2.3, has been

ϖ(s)ξ(s)=(β1μ+1)ηs(β1μ+1)η0sψ(τ)τ((β1μ+1)/η)1=(β1μ+1)ηs(β1μ+1)η0s[(3/2π1)+3/2(1π)11+τ]τ((β1μ+1)/η)11+τ=(β1μ+1)ηs(β1μ+1)/η0s(3/2π1)τ((β1μ+1)/η)1+3/2(1π)(β1μ+1)ηs(β1μ+1)η0sτ((β1μ+1)/η)11+τ=(3/2π1)+3/2(β1μ+1)(1π)ηs(β1μ+1)ηζ((β1μ+1)η),
then
(Mσ,μn,ςϒ(s))ξ(s)=(3/2π1)+3/2(β1μ+1)(1π)ηs(β1μ+1)/ηζ((β1μ+1)/η).

Theorem 3.2.

Given that ξ is a convex function in Δ with ξ(0)=1 and ψ(s)=ξ(s)+sξ(s). If ϒΛ , σN,μ>0;n,ς0,0π<1 satisfies the subordination (Mσ,μn,ςϒ(s))ψ(s), then

(13)
Mσ,μn,ςϒ(s)sξ(s),(sΔ).

Proof.

Let ϖ(s)=Mσ,μn,ςϒ(s)s

ϖ(s)=s+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsηs,ϖ(s)=1+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsη1ϖ(s)=1+ϖηsη+ϖη+1sη+1+(Mσ,μn,ςϒ(s))=ϖ(s)+sϖ(s).

Consequently, with the help of the connection Eq. (13) grows

ϖ(s)+sϖ(s)ψ(s)=ξ(s)+sξ(s).

Utilizing Lemma 2.2, previously

ϖ(s)ξ(s).

Through the use of ϖ(s)=Mσ,μn,ςϒ(s)s , we obtain

Mσ,μn,ςϒ(s)sξ(s).

Theorem 3.3.

If σN,μ>0;n,ς0 as well as 0π<1, then Rσ,μn+1,ς(π)Rσ,μn,ς(β) such that

(14)
ε=(3/2π1)+3/2(1π)(β1μ+1)ηζ((β1μ+1)/η),ζ=0sτx11+τ.

Proof.

Assume ϒ is in ϒRσ,μn+1,ς(π). Next, based on Eq. (8), there is R(Mσ,μn,ςϒ(s))>π this is equivalent to

(Mσ,μn+1,ςϒ(s))ψ(s)=1+(3/2π1)s1+s.

Applying Theorem 3.1, we arrive at

(Mσ,μn,ςϒ(s))ξ(s)=(3/2π1)+3/2(β1μ+1)(1π)ηs(β1μ+1)/ηζ((β1μ+1)/η).

Since ξ(Δ) is symmetric when compared to the real direction and ξ is convex, we are able to deduce that

Re(Mσ,μn,ςϒ(s))>Reξ(1)=ε=ε(π,β1,μ,η)=(3/2π1)+3/2(β1μ+1)(1π)ηζ((β1μ+1)/η),
where
ξ(1)=(β1μ+1)η01[1+(3/2π1)τ1+τ]τ((β1μ+1)/η)1=(β1μ+1)η01[(3/2π1)+3/2(1π)11+τ]τ((β1μ+1)/η)11+τ=(β1μ+1)η01(3/2π1)τ((β1μ+1)/η)1+3/2(1π)(β1μ+1)η01τ((β1μ+1)/η)11+τ=(3/2π1)+3/2(β1μ+1)(1π)ηζ((β1μ+1)/η)

It leads us to the conclusion that Rσ,μn+1,ς(π)Rσ,μn,ς(β). The evidence is finished.

Theorem 3.4.

Let ψ be a convex function in Δ , ψ(0)=1,0π<1, and ψ(s)=1+(3/2π1)s1+s. If σ,μ>0;n,ς0,ϒΛ satisfies the subordination (Mσ,μn,ςϒ(s))ψ(s), then

Mσ,μn,ςϒ(s)sξ(s)=(3/2π1)+3/2(1π)ln(1+s)s,(sΔ).

The function ξ is convex as well as the most prevailing.

Proof.

Suppose

(15)
ϖ(s)=Mσ,μn,ςϒ(s)s=s+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsηs,=ϖ(s)=1+ϖηsη+ϖη+1sη+1+.

By Eq. (15) in relation to ϖ , we get

(16)
(Mσ,μn,ςϒ(s))=ϖ(s)+sϖ(s),(sΔ).

By applying Eq. (16), differential subordination (Mσ,μn,ςϒ(s))ψ(s), is obtained

ϖ(s)+sϖ(s)ψ(s)=1+(3/2π1)s1+s,(sΔ).

Utilizing Lemma 2.3, has been

ϖ(s)ξ(s)=1s0sψ(τ)=1s0s(1+(3/2π1)τ1+τ)=1s0s[(3/2π1)+3/2(1π)11+τ]=1s0s(3/2π1)+3/2(1π)s0s11+τ=(3/2π1)+3/2(1π)ln(1+s)s.

With the help of Eq. (15), we had

Mσ,μn,ςϒ(s)sξ(s)=(3/2π1)+3/2(1π)ln(1+s)s.

Theorem 3.4, has been fully proved.

Theorem 3.5.

If ψ is convex function in Δ and ψ(0)=1,0π<1,ψ(s)=1+(3/2π1)s1+s, ϒΛ,σ,κ>0;n,ς0 satisfies the subordination

(17)
1Mσ,μn,ςϒ(s)(Mσ,μn,ςϒ(s))[(Mσ,μn,ςϒ(s))]2ψ(s),
then
Mσ,μn,ςϒ(s)s(Mσ,μn,ςϒ(s))ξ(s)=(3/2π1)+3/2(1π)ln(1+s)s.

Proof.

Suppose

ϖ(s)=Mσ,μn,ςϒ(s)s(Mσ,μn,ςϒ(s)),ϖ(s)=s+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsηs(1+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsη1),
so that with the help of Eq. (17) becomes
ϖ(s)+sϖ(s)ψ(s)=1+(3/2π1)s1+s,(sΔ).

By Lemma 2.3 allows us to have

ϖ(s)ξ(s)=1s0sψ(τ)=1s0s(1+(3/2π1)τ1+τ)=1s0s[(3/2π1)+3/2(1π)11+τ]=(3/2π1)+3/2(1π)ln(1+s)s,
then
Mσ,μn,ςϒ(s)s(Mσ,μn,ςϒ(s))ξ(s)=(3/2π1)+3/2(1π)ln(1+s)s.

Theorem 3.6.

If ϒΛ and suppose that ξ is an analytic function that fulfills the next inequality R{1+sψ(s)ψ(s)}>12, and ψ(0)=1,ψ(0)0,σN,μ>0;n,ς0 satisfies the subordination

(18)
(Mσ,μn,ςϒ(s))ψ(s),(sΔ),
then
Mσ,μn,ςϒ(s)sξ(s)=1s0sψ(τ).

Proof.

Suppose

(19)
ϖ(s)=Mσ,μn,ςϒ(s)s=s+η=2(β1μς)η1(β2)η1(βn)η1(π1)η1(π2)η1(πσ)η1(1μ+η1)ς+1eηsηs,ϖ(s)=1+ϖηsη+ϖη+1sη+1+.

By Eq. (19) in relation to w, we get

(20)
(Mσ,μn,ςϒ(s))=ϖ(s)+sϖ(s),(sΔ).

Subordination Eq. (18), when applied to Eq. (20), grows

ϖ(s)+sϖ(s)ψ(s).

By Lemma 2.3 allows us to have

ϖ(s)ξ(s),
in other words,
Mσ,μn,δϒ(s)sξ(s)=1s0sψ(τ).

Theorem 3.7.

If ϒΛ and suppose ξ be convex function in Δ , ξ(0)=1 and ψ(s)=ξ(s)+sξ(s) , σN,μ>0;n,ς0 , 0π<1 satisfies subordination

(21)
1Mσ,μn,ςϒ(s)(Mσ,μn,ςϒ(s))[(Mσ,μn,ςϒ(s))]2ψ(s),(sΔ),
then
(22)
Mσ,μn,ςϒ(s)s(Mσ,μn,ςϒ(s))ξ(s).

Proof.

Suppose

ϖ(s)=Mσ,μn,ςϒ(s)s(Mσ,μn,ςϒ(s)),pH[1,1].

Taking the product of both perspectives gives us

ϖ(s)+sϖ(s)=1Mσ,μn,ςϒ(s)(Mσ,μn,ςϒ(s))[(Mσ,μn,ςϒ(s))]2,
so that with the help of Eq. (21) becomes
ϖ(s)+sϖ(s)ψ(s)=ξ(s)+sξ(s),(sΔ).

By Lemma 2.2, we obtain

ϖ(s)ξ(s),
then
Mσ,μn,ςϒ(s)s(Mσ,μn,ςϒ(s))ξ(s).

4. Conclusions

There are many fascinating discoveries regarding harmonic multivalent functions derived from differential operators. The study concentrated on a subclass of analytical univalent functions related to the concept of differential subordination. Everyone looked at a few differential subordination and superordination outcomes, such as a class determined by a dimension for univalent meromorphic functions inside the open unit disc. Learn about geometrical characteristics such as coefficient border, coefficient disparities, distortion theorem, closing theorem, severe points, starlikeness radii, convexity, near-perfect convexity, and combining principles. An analysis is conducted on the concept of the differential subordination subclass of analytical univalent functions. Utilizing a particular class of univalent functions stated on a particular space of univalent functions stated on the open unit disc, we examined certain findings on differential subordination as well as superordination. We found several properties of subordinations as well as superordinations connected to the notion of Hadamard product by using characteristics of the operator. We examined various facets of subordinations as well as superordinations through a novel operator, Mσ,μn,ςϒ(s) .

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Majel MS and Hameed MI. Study analytical function subordination properties by applying a novel linear operator [version 1; peer review: awaiting peer review]. F1000Research 2025, 14:1479 (https://doi.org/10.12688/f1000research.174492.1)
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