Abstract
By using the most generalized gamma function (parametric gamma function, or p-gamma function), we present the most generalized Rabotnov function, called the p-Rabotnov function. Consequently, new fractal–fractional differential and integral operators of a complex variable in an open unit disk are defined and investigated analytically and geometrically. We address some inequalities involving the generalized fractal–fractional integral operator in some spaces of analytic functions. A novel complex fractal–fractional integral transform (CFFIT) is presented. A normalization of the proposed CFFIT is observed in the open unit disk. Examples are illustrated for power series of analytic functions.
Keywords:
fractional calculus; fractal calculus; fractional difference operator; fractal–fractional differential operator; fractal–fractional calculus; complex transform; subordination and superordination MSC:
28A80; 26A33; 30C45
1. Introduction
The phrase “complex integral transform” encompasses a wide range of mathematical methods that include complex integrals. In physics and engineering, the Laplace transform is one of the greatest commonly utilized instances of a complicated integral transform. Recently, a number of studies that have made use of methods originally developed in a physical setting have concentrated on offering comprehensive accounts of social and environmental phenomena. Researchers’ ability to devise strategies has led to structures like these [1]. Such methods are used in movement theory, hyperactive complicated processes, complex fluid systems, chaotic complex systems, complex Lorenz-like patterns seen in optical physics, and the study of the nonclinical instability of the meteorological processes in the surrounding atmosphere [2]. Most of these complex transformations are structured by using the gamma function or are reduced by it. Numerous fields in science, mathematics, and industry use the gamma function, including integration, probability, and complex analysis. It has links to many mathematical ideas and functions, including the beta function and the digamma function, and is an important instrument in the exploration of special functions. As seen in [3], the p-gamma function (generalized gamma or parametric gamma function), also referred to as the modified gamma function, can be observed as follows:
and also satisfies the following properties
We proceed to define the p-Rabotnov function by using as follows:
where the Mittag-Leffler function is denoted by . Figure 1 shows a plot of the p-Rabotnov function for different values of its parameters. It is evident that we acquire the regular Rabotnov function for (see [4]).
Figure 1.
A complex plot of the Rabotnov function for some values of when and .
By using the above generalized special function, we present a set of fractal–fractional operators of a complex variable.
2. p-Fractal–Fractional Operators
The subsequent new p-fractal–fractional operators are required.
Definition 1.
The complex p-Riemann–Liouville fractal–fractional differential operator is developed for the analytic function as follows:
where
Moreover, the Caputo formula is defined as follows:
Correspondingly, we define the following integral:
Note that when and , the above operators are reduced [5].
Example 1.
Let Since
where is the p-Mittag-Leffler function, where
clearly,
As a consequence, based on the definition of , with
we obtain
Meanwhile, for we obtain
With the following presumptions, if we use the fractal–fractional integral operator
we obtain
Integral Inequalities
This part deals with some inequalities involving .
Definition 2.
Let The Bergman space is the set of all analytic functions g in the open unit disk satisfying the norm
Proposition 1.
Let . If
then
Proof.
Our proof is based on Young’s inequality concerning integral operators.
Hence, □
Definition 3.
The analytic function g in the open unit disk is called in the space of the bounded analytic function if it satisfies the norm
Proposition 2.
Let . If
then
Proof.
A computation yields
Hence, □
Definition 4.
The analytic function g in the open unit disk is called in the Bloch space of the analytic function if it satisfies the norm
Proposition 3.
Let . If
then
Proof.
A computation yields
Hence, □
3. Complex Fractal–Fractional Integral Transform (CFFIT)
Numerous fields of science and engineering use complex integral transformations, which are strong mathematical instruments. These examples demonstrate how complicated integral transforms may be applied to solve a wide range of issues in a variety of domains, offering insights into a range of phenomena and assisting in mathematical modeling and analysis.
From this perspective, we define the following CFFIT.
Definition 5.
An equivalent generator of order , the p-fractal–fractional integral operator is created via the following structure:
Proposition 4.
Assume that is a complex Hilbert space of analytic functions. If with then is is accretive operator, i.e.,
Proof.
Based on the assumptions of this proposition, we obtain
where is an accretive operator. □
Normalization Form
The p-fractal–fractional integral transform yields the following observation:
Let
Then, by setting where in the analytic function , we calculate the CFFIT as follows:
where If is normalized by can be normalized as follows:
Here, we denote the class of normalized analytic functions in using
Proposition 5.
Consider the operator where If , then is convex. In addition, if , then is starlike.
Proof.
It is well known that [6,7]
A computation implies that
Thus, is convex. The same is true for the second part. □
The next proposition shows the upper bound of the CFFIT in the open unit disk, when g achieves some special geometric properties. We prove that the suggested normalized operator is bounded in the open unit disk by the special generalized Fox–Wright function for some geometric functions .
Proposition 6.
Consider the operator where
If g is convex, then
Proof.
Since g is convex, for all n (see [8]). Based on the definition of we obtain
□
Proposition 7.
Consider the operator where
If g is starlike, then
Proof.
Since g is starlike, for all n (see [8]). Based on the definition of we obtain
□
4. Special Formulas Involving CFFIT
In this section, we deal with a list of special formulas that contain the suggested CFFIT. These formulas belong to a class of analytic functions in the open unit disk (see [8]). For the class of analytic functions satisfies the main conditions and . This class is denoted by This class achieves the inclusion property whenever Obviously, the subclasses of starlike and convex functions are in Moreover, two analytic functions, and , are subordinated, denoted by , if and
To prove our results, we need the following preliminary [9]
Lemma 1.
For and positive integer n, let
- i.
- For the following relation is satisfied In addition, for and , there are two constants, and , with satisfying the relation
- ii.
- For and , there is a constant with such that
- iii.
- If with , then ; then, Moreover, if and , then
Lemma 2.
Let h be a convex function with and let be a complex number with If and then where
Theorem 1.
For , if one of the following relations is satisfied
- ;
then for the indicated .
Proof.
Define the following analytic function
The first condition implies that Thus, according to Lemma 1.i, where we obtain , which concludes that .
The next subordination states that
Again according to Lemma 1.i, there is a constant with with
This implies that
We proceed with the third relation, which yields
According to Lemma 1.ii, there is a constant satisfying such that for some It follows from (2) that therefore, the Noshiro–Warschawski and Kaplan Theorems imply that is univalent and of bounded boundary rotation in . By differentiating (1) and calculating the real number, we obtain
According to Lemma 1.ii, we confirm that
Lastly, based on logarithmic differentiation (1) and considering the real number, we observe that
Hence, Lemma 1.iii states that That is,
for some . □
Theorem 2.
Assume that f is convex such that . If
then
and this outcome is sharp.
Proof.
Applying Lemma 1 is our goal. Formulate the next function:
This concludes that
As a result, we infer the subsequent subordination:
Considering Lemma 1, we obtain
and f is the best dominant. □
Theorem 3.
Consider the operator If
then for specific Additionally, it is univalent and of bounded boundary rotation in .
Proof.
Formulate the analytic function v as in (3). A calculation indicates that
Lemma 1.ii shows that there is a constant ℓ depending on ℘ with . By letting we have for some It appears from (4) that ; as a consequence, and in view of the Noshiro–Warschawski and Kaplan Theorems, is univalent and of bounded boundary rotation in . □
Theorem 4.
Assume that for a function g with And the convex analytic function ς with . Then, for the function
the subordination
brings
and this result is sharp.
Proof.
Our proof is based on Lemma 2. In view of we obtain
Based on this assumption, we obtain
Consider
One can observe that
Lemma 2 yields that
and is the best dominant. □
5. Conclusions
The above investigation consists of two parts. The first one presents the generalized p-fractal–fractional operators using the Rabotnov function. Some properties are presented for these operators. In the second part, a complex integral transform is defined under the definition of the generalized p-fractal–fractional calculus. Under some conditions, we showed that the transform is accretive in a complex Hilbert space. To discuss its geometric conduct in the open unit disk, the normalization formula is presented. Sufficient conditions for these properties are computed by introducing a list of coefficient inequalities.
Author Contributions
Conceptualization, R.W.I., S.S. and Á.O.P.-S.; Writing—original draft, R.W.I., S.S. and Á.O.P.-S.; Writing—review & editing, R.W.I., S.S. and Á.O.P.-S. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Data Availability Statement
The data are contained within the article.
Conflicts of Interest
The authors declare no conflicts of interest.
Abbreviations
The following abbreviations are used in this manuscript:
| CFFIT | Complex fractal–fractional integral transform |
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