Abstract
Using the derivative operators’ -analogs values, a wide variety of holomorphic function subclasses, -starlike, and -convex functions have been researched and examined. With the aid of fundamental ideas from the theory of -calculus operators, we describe new -operators of harmonic function in this work. We also define a new harmonic function subclass related to the Janowski and -analog of Le Roy-type functions Mittag–Leffler functions. Several important properties are assigned to the new class, including necessary and sufficient conditions, the covering Theorem, extreme points, distortion bounds, convolution, and convex combinations. Furthermore, we emphasize several established remarks for confirming our primary findings presented in this study, as well as some applications of this study in the form of specific outcomes and corollaries.
Keywords:
convolutions; q-Mittag–Leffler; Le Roy-type Mittag–Leffler; harmonic function; holomorphic functions; univalent function; q-calculus MSC:
30C45; 30C50
1. Introduction
Quantum calculus, also known as (-calculus), is a branch of mathematics that extends classical calculus to the quantum realm. It is an effective tool for studying the behavior of quantum systems and has numerous applications in mathematics, engineering, physics, and finance. Quantum calculus has recently grown in importance as a tool for understanding harmonic functions, which are essential to the study of mathematics, physics, and engineering. The study of harmonic functions using -calculus offers fresh and creative approaches to comprehending and simulating physical and engineering systems. It was demonstrated that the study of fractional harmonic functions, which are a generalization of classical harmonic functions, makes excellent use of -calculus.
To determine coefficient estimates and inclusion relations, harmonic classes of holomorphic functions have recently been created and investigated. Yousef et al. [1] defined a new subclass of univalent functions and acquire a few geometrical properties using a generalized linear operator. Using a certain convolution -operator, Srivastava et al. [2] introduced two new families of harmonic meromorphically functions and conducted investigations into the inclusion features.
Srivastava et al. [3] developed and investigated a new class of harmonic functions involving Janowski functions using a -derivative operator. Khan et al. (2007) [4], on the other hand, employed a new class of harmonic functions involving a symmetric Sălăgean -derivative operator. Studies on a novel class of harmonic functions related to starlike harmonic functions are carried out using the concepts of subordination and Ruscheweyh derivatives, see [5,6,7,8,9].
In 1990, Ismail et al. [10] established a class of complex-valued functions that are holomorphic on the open unit disk , therefore incorporating -calculus into the theory of holomorphic univalent functions with the normalizations , and on ℶ for every . Several authors employed the theory of holomorphic univalent functions and -calculus as a result of the influence of these writers; see, for instance [11,12,13,14,15,16].
The complex-valued function is said to be harmonic in ℶ if both v and u are real-valued harmonic functions in ℶ. Furthermore, the complex-valued harmonic function can be expressed as , where ℑ and ℏ are holomorphic in ℶ. In particular, ℏ is known as the holomorphic part, and ℑ is known as the co-holomorphic part of .
Before using -calculus and harmonic univalent functions, it is necessary to understand the notation and terminology for harmonic univalent functions.
A function where ℏ and ℑ, respectively, are the holomorphic and co-holomorphic parts, is locally univalent and sense preserving in ℶ if and only if ) in ℶ.
The continuous complex-valued functions defined in ℶ with the following form
Let and its subclass are defined as (see, for details [17,18,19,20,21]),
If in ℶ, then class is reduced to the class of normalised holomorphic functions which are univalent in ℶ, (for more details, see [22]).
Ahuja et al. [23] presented the -harmonic class of functions in ℶ denoted by .
Definition 1
([23]). A harmonic function as in (1) is said to be -harmonic sense preserving and locally univalent in ℶ, denoted by , iff the second dilatation satisfies the condition
Note that when , then reduces to the well known family .
Furthermore, The class consisting of functions , where
2. Preliminaries and Definitions
In this section, we provide some fundamental definitions and properties of -calculus that are applied throughout this investigation. These are based on the assumption that .
Definition 2
([24]). Let . Then the denotes the basic (or -) number, defined by
It is obvious from Definition 2 that .
Definition 3
([24]). The q-derivative (or q-difference operator) of a function f is defined by
We note that , if f is differentiable at .
For a parameter with and . Then, the generalized Mittag–Leffler-type function, introduced by Wiman [25] by
Recently, Schneider [26] and independently Garra and Polito [27], introduced Le Roy-type Mittag–Leffler function, defined as
For , In 2014, Sharma and Jain [28] defined the -Mittag–Leffler-type function, by
where and is the -gamma function can also be defined by
Motivated by Gerhold [29] and Garra and Polito [27], we define the -analog of Le Roy-type Mittag–Leffler function, by
where , .
The normalization of the -analog of Le Roy-type Mittag–Leffler function can be defined by
where , .
Next, we define the following new -operators of of harmonic function by
where
Below is an illustration that shows how we introduce the class of harmonic univalent functions by using the operator .
Definition 4.
For , a function f as is in (1) is said to be in the class of harmonic convex function of order ℵ in ℶ, if it satisfies the condition
Here, the class is defined by .
Remark 1.
When , then reduces to , known as -harmonic convex functions of order ℵ introduced by Ahuja et al. [23]. Furthermore, when and , then reduces to , known as harmonic convex functions of order ℵ (see [30,31,32]). Furthermore, when , and , then reduces to the traditional , known as convex functions of order ℵ, studied in 1936 [33]. Moreover, when and , then is reduced to [34].
3. Sufficient Coefficient Condition
In this section, we start with a sufficient coefficient condition for functions in the class .
Theorem 1.
Let and . If as is in and satisfies the condition
where . Then, is harmonic sense preserving and univalent in the open unit disk ℶ and so, .
Proof.
Let be as is in (1) and satisfies the condition (10), then is sense preserving in ℶ if it satisfies . Since
it follows that , by Definition 3.
To show is univalent in ℶ, for , we observe that
which proves the univalence.
Now, we show that . Then, from Definition 4, we can write (9)
where
and
It is suffices to demonstrate that
using the fact that is true if and only if .
Remark 2.
When , Theorem 1 reduces to the corresponding convolution condition obtained in [23]. Furthermore, for , and , Theorem 1 reduces to the matching convolution condition found in [35].
Theorem 2.
Proof.
Since , this Theorem 2 merely requires that we prove the “only if” clause. Due to this, for functions of the form (3), the condition (9) is equivalent to
For all values of , , the aforementioned necessary condition (13) has to be true. By choosing the values of on the positive real axis where , we must have
The numerator in (14) is negative for j sufficiently near to 1 if condition (12) does not hold. Hence, there is a point in for which the quotient in (14) is negative. As this conflicts with the necessary predicate for , the proof is complete. □
Next, we determine the extreme points of closed convex hulls of , denoted by .
4. Extreme Points
In this section, we determine extreme points for the class .
Theorem 3.
Let as is in (3). Then, if and only if , where
and where and . The extreme points of are specifically and .
Proof.
For of the form where , we have
Then, because
Conversely, suppose . In view of (12), we have
Set
and
By Theorem 2, . Therefore we define . Consequently, we obtain as required. □
5. Convolution and Convex Combinations
The Hadamard products (or convolution) of two functions and is defined by
Next, we show that the class is closed under convolution.
Theorem 4.
For , suppose and . Then, .
Proof.
Let and , then
Since , it follows from Theorem 2 that and . Therefore, we have
In view of Theorem 2, it follows that . □
We now show that is closed under a convex combination of its members.
Theorem 5.
The class is closed under convex combination.
Proof.
Let for where is given by
Then, by Theorem 2, we have
For and , the convex combination of may be written as
Using (15), we have
Furthermore, by Theorem 2, we have . □
6. Distortion Bounds and Covering Theorem
The following Theorem contains distortion bounds for functions in the class .
Theorem 6.
If then for , we have
and
Proof.
The inequality (16) leads to the covering conclusion shown below.
Corollary 1.
If then
Remark 3.
The result for -harmonic convex functions of order ℵ derived in [23] is the result for , as shown by the covering Theorem 6 in Corollary 1. Moreover, the covering Theorem 6 in Corollary 1 offers the usual conclusion for harmonic convex functions found in [36] with the conditions and . In addition, for , , , Corollary 1 yields the following result given in [36].
Remark 4.
If then {} .
7. Conclusions
Numerous academics have recently applied -calculus to the study of geometric functions, creating new subclasses of - starlike, -convex, and harmonic functions. Using the concept of Le Roy-type Mittag–Leffler functions, a novel class of harmonic functions was established in this study. We established some novel results for this newly defined class, such as extreme points, convolution and convex combinations, distortion limitations, and the covering theorem, as well as necessary and sufficient conditions. Future studies on harmonic functions and symmetric -calculus operators will be inspired by the findings of this study.
Author Contributions
Conceptualization, A.A. (Abdullah Alsoboh) and A.A. (Ala Amourah); methodology, A.A. (Ala Amourah); validation, A.A. (Abdullah Alsoboh), A.A. (Ala Amourah), M.D. and C.A.R.; formal analysis, A.A. (Abdullah Alsoboh); investigation, A.A. (Abdullah Alsoboh), A.A. (Ala Amourah) and M.D.; writing—original draft preparation, A.A. (Abdullah Alsoboh) and A.A. (Ala Amourah); writing—review and editing, C.A.R. and A.A. (Abdullah Alsoboh); supervision, M.D. All authors have read and agreed to the published version of the manuscript.
Funding
The authors would like to thank the Deanship of Scientific Research at Umm Al-Qura University for supporting this work by Grant Code:(23UQU4320576DSR001).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
No data were used to support this study.
Conflicts of Interest
The authors declare no conflict of interest.
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