Abstract
In this article, the present study employs the utilization of the concepts pertaining to -symmetrical functions, Janowski type functions, and q-calculus in order to establish a novel subclass within the open unit disk. Specifically, we delve into the examination of convolution properties, which serve as a tool for investigating and inferring adequate and equivalent conditions. Moreover, we also explore specific characteristics of the class , thereby further scrutinizing the convolution properties of these newly defined classes.
Keywords:
analytic functions; (x,y)-symmetrical functions; q-calculus; Hadamard product; (ρ,q)-neighborhood MSC:
30C45; 30C50
1. Introduction
The theory of functions exhibiting -symmetry has a wide range of intriguing applications. For instance, these functions are useful in exploring the set of fixed points of mappings, estimating the absolute value of certain integrals, and deriving results akin to Cartan’s uniqueness theorem for holomorphic mappings, as demonstrated in []. The intrinsic properties of -symmetrical functions are of great interest in the field of Geometric Function Theory. In this work, we present fundamental definitions and concepts related to -symmetrical functions. We assume that y is a fixed integer and set . Furthermore, we definedomain to be a y-fold symmetric domain if . Function h is referred to as a y-symmetrical function if, for every ,
In 1995, Liczberski and Polubinski [] introduced the notion of -symmetrical functions for () and . Consider a y-fold symmetric domain and let x be any integer. Function is deemed -symmetrical if for every , The collection of all -symmetrical functions is denoted by . Furthermore, it is worth noting that , and represent families of even, odd, and -symmetrical functions, respectively.
Theorem 1
([], Page 16). For every mapping , and a y-fold symmetric set k, then
Remark 1.
Let be the collection of all functions that possess analyticity within the open unit disk and let denote a particular subfamily, which is characterized by class , and takes the form of
consider as the set of all functions belonging to that are univalent within k. The convolution or Hadamard product of two analytic functions h and g, both belonging to the set, can be expressed as
where h is defined by Equation (4) and Those interested in the Hadamard product and its generalization are encouraged to refer to sources [,]. To introduce new classes of q-Janowski symmetrical functions defined in k, it is necessary to first review the relevant concepts and notations pertaining to Janowski-type functions, -symmetrical functions, and quantum calculus, also known as q-calculus. In his work [], Janowski introduced the class which pertains to a given It is said that h belongs to if and only if , where . Here, represents the family of Schwarz functions, that is,
In [], Jackson presented and examined the notion of the q-derivative operator where q satisfies the condition . The operator is defined as follows
Alternatively, as expressed in (6), it can be written as
where
Note that as , . For a function we can note that
Then,
where is the ordinary derivative.
The q-integral of a function h, which was presented by Jackson [], is regarded as a right inverse given the condition that
provided that the series converges. Ismail et al. [] introduced the initial link between quantum calculus and geometric function theory. In recent years, numerous authors have utilized the quantum calculus approach to investigate the geometric properties of several subclasses of analytic functions. For instance, Naeem et al. [] delved into the subclass of q-convex functions, while Srivastava et al. [] examined subclasses of q-starlike functions. Additionally, Alsarari and Alzahrani [] explored the convolution conditions of q-Janowski symmetrical function classes. Moreover, Ovindaraj and Sivasubramanian in [] discovered subclasses related to q-conic domains, and several recent studies can be found in [,,]. Khan et al. [] employed the symmetric q-derivative operator, while Srivastava [] published a survey-cum-expository review paper that is highly beneficial to researchers.
Proposition 1.
For n and m any real (or complex) constants and we have
- 1
- ,
- 2
- 3
The function h is denoted as -spiral-like if the real part of is greater than zero. Here, represents a real number such that its absolute value is less than In recent research conducted by Al sarari et al. [,], numerous intriguing findings were obtained for various classes by utilizing the concept of -symmetrical functions and the q-derivative. Consequently, we combine the notion of -symmetrical functions, the q-derivative, and Janowski-type functions to establish the ensuing classes.
Definition 1.
For arbitrary fixed numbers and λ, let denote the family of functions which satisfies
where is defined in (1).
The aforementioned classes can be reduced to well-established classes that were originally defined by Janowski []. The class =, which was introduced and extensively studied by Agrawal and Sahoo [], can be associated with the class Se1, = , first introduced by Ismail et al. []. The class = represents the widely recognized class of starlike functions of order = , as introduced by Robertson []. Lastly, the class can be attributed to the work of Nevanlinna []. We denote by the subclass of consisting of all functions h such that
We must call to mind the subsequent concept of a neighborhood
Definition 2.
For any , the ρ-neighborhood of function h can be defined as:
For , we can see that
Remark 2.
- If we substitute in Definition 2 we obtain the concept initially introduced by Goodman [] and later generalized by Ruscheweyh [].
- If we substitute in Definition 2, we arrive at the definition of a neighborhood with q-derivative , where is defined by Equation (7).
Ruscheweyh [] demonstrated, among other findings, that for all , with ,
2. Main Results
In this section, we investigate the convolution conditions for the class of convex functions in Theorem 2, which will be used to get the convolution conditions for the class of star-like functions in Theorem 3, which is the equivalent of Remark 4. Theorem 5, with its application of Corollary 2, will be used as a supporting result to deduce the sufficient condition of Theorem 4 and Corollary 1, which will be used to get the neighborhood results of Theorems 6 and 7.
Proof.
Remark 3.
Ganesan et al. in [] and Silverman et al. in [] demonstrated the following result for and various values of and β.
Proof.
Since if and only if , we have
where is defined by (13). As a result, Theorem 3 leads to the conclusion. □
Remark 4.
Take note that Theorem 3 makes it simple for us to derive the corresponding condition for a function if and only if
where has the form
Corollary 1.
Let , then if and only if
Proof.
Let with satisfying inequality (20).
Let g given in Remark 4 and
Applying Remark 4, we get . Conversely, let and let
Then, using Theorem 3, we obtain
Let , then there exists , such that
which is a contradiction. Hence, □
The sufficient condition theorem can be driven by using Remark 4.
Theorem 4.
Proof.
Theorem 5.
Let f be a convex function and let and satisfies inequality
then, .
Proof.
Corollary 2.
Proof.
Since
We note that . It is simple to confirm that it is convex. Now, use Theorem 5 to get . □
Remark 5.
The results in [] are obtained for and in Theorem 4.
Theorem 6.
Let , and for any number η that is complex with , if
Then
where .
Proof.
We suppose that a function f defined by is in the class . We only need to prove that to prove Theorem 6. This claim will be proved in the next three steps.
The well-known result proved by Ruscheweyh in [] can be obtained when and , as shown in the above theorem.
Theorem 7.
Let , for . Then
where, c is a non-zero real number with and g is defined in Remark 4.
3. Conclusions
Motivated by recent applications of the theory of -symmetrical functions and the concept of q-calculus in geometric function theory, we have employed these two concepts to define and analyze the classes and for -spiral-like functions in the open unit disk. Specifically, we have explored a convolution property, which will serve as a foundation for further investigation. We have also derived the sufficient condition and equivalent condition. Additionally, we have examined various neighborhood results for the class . The methodology presented in this paper can be readily applied to establish multiple classes with distinct image domains. The utilization of symmetric q-calculus, the Janowski class, and the essential q-hypergeometric functions offers ample opportunities for research in various fields.
Author Contributions
The idea for the current study was developed by researchers F.A.; M.I.F. and A.A.A. verified the information and made a number of suggestions that greatly enhanced the current article. Each author contributed after reading the final draft. All authors have read and agreed to the published version of the manuscript.
Funding
The author extends their appreciation to the Deanship for Research and Innovation Ministry of Education in Saudi Arabia for funding this research through project number 445-9-223.
Data Availability Statement
Not applicable.
Conflicts of Interest
The authors declare no conflict of interest.
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