Abstract
Time scales have been the target of work of many mathematicians for more than a quarter century. Some of these studies are of inequalities and dynamic integrals. Inequalities and fractional maximal integrals have an important place in these studies. For example, inequalities and integrals contributed to the solution of many problems in various branches of science. In this paper, we will use fractional maximal integrals to establish integral inequalities on time scales. Moreover, our findings show that inequality is valid for discrete and continuous conditions.
MSC:
47B38; 34N05; 35A23
1. Introduction
The founder of the study of dynamic equations on time scales is Stefan Hilger [1]. Recently, the inequalities and dynamic equations on time scales have received great attention. Dynamic equations and inequalities have many applications in quantum mechanics, neural networks, heat transfer, electrical engineering, optics, economy and population dynamics [2,3,4,5]. It is possible to give an example from the economy, seasonal investments and income [6]. Many mathematicians have demonstrated various aspects of integral inequalities on time scales [7,8]. The most important examples of time scale studies are differential, difference and quantum calculus [9], i.e., when , and where .
Fractional calculus is an extended version of non-integer integrals and derivatives. In time scales, Lebesgue spaces and different spaces, the subject of fractional integrals has been studied by many mathematicians [10,11,12,13,14,15,16,17,18,19]. We consider the functional [20]:
where and are two synchronous integrable functions on , (i.e., ).
The main subject of our article is to create new fractional inequalities by using fractional maximal integral operators and synchronous functions on time scales. In addition, our findings include continuous inequalities and corresponding discrete analogs.
The organization of this article is as follows. In Section 2, we will give some definitions of the -maximal type fractional integral operator on time scales. In Section 3, we will create new fractional inequalities by using fractional maximal integral operator and synchronous functions on time scales. In Section 4, we show a few applications of our results.
2. Preliminaries
Some basic concepts related to time scale are given below without proof. We recommend that the reader refer to the [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25] monographs for details.
Definition 1.
[21] Given an open set and , . Fractional maximal operator is defined as follows
where the supremum is again taken over all balls which contain . In the limiting case , the fractional maximal operator reduces to the Hardy–Littlewood maximal operator.
Definition 2.
[21] Let and a measurable function. is composed of all measurable functions on such that
for any . The norm in space is the generalization of the norm in space ( is constant). The Luxemburg norm in space is defined as follows.
At the same time becomes a Banach space.
Definition 3.
[22] Let and be two integrable functions on . If for any
then and are called synchronous real-valued functions on .
Definition 4.
[23] A time scale is an arbitrary nonempty closed subset of the real numbers . We define the forward jump operator by for and we define the backward jump operator as defined by for .
If , we say that is right-scattered and if , we say that is left-scattered. Moreover, if , then is called right-dense and if , then is called left-dense. such that is called graininess mapping.
If has a left-scattered maximum , then . Otherwise . Briefly
Along the same lines
Definition 5
[23] A function is said to be right-dense continuous if it is right continuous at each right-dense point and there exists a finite left limit at all left-dense points, and is said to be differentiable if its derivative exists.
The space of rd-continuous functions is denoted by .
Definition 6.
[23] The generalized polynomials, that also occur in Taylor’s formula are , functions. The functions are , . Given and are
and
We claim that for
Definition 7.
[24] If and , then
For we can define the time scale -maximal type fractional integral
where and (for details on Lemma 2, see [25]) Lebesgue -integrable functions on , .
Lemma 1.
(Lemma 2, [25]) Let , . Assume is additionally Lebesgue -measurable on . Then .
3. Main Result
We now present the inequalities with respect to fractional maximal integral type operators and their norms in the variable exponential Lebesgue space.
Theorem 1.
Let and be two real-valued synchronous functions on . For , , we have
Proof.
If and are two synchronous functions on , then, for ,
Hence
For multiplying both sides of (2) by we have
If we take the integral of both sides of (3) through we get
Since and are independent from , we can take them out of integral.
Thus, the following is obtained
If we take instead of ( and ) in Definition 6, we get the following.
Similarly,
We know that,
If we take the supremum of both sides of (4) over , we get the following
Due to () Definition 7, we get following
For multiplying both sides of (5) by we have
If we take the integral of both sides of (6) through we get
Since , , and are independent from , we can take them out of integral.
If we take instead of and if we take instead of ( and in the Definition 6), we get the following
Thus, the following is obtained
Hence from Definitions 5 and 6 the following is obtained
Finally we get
□
Theorem 2.
Let and be two real-valued synchronous functions on . For , , we have
Proof.
If and are two synchronous functions on , then for we have
Hence
For multiplying both sides of (7) by we have
If we take the integral of both sides of (8) through we get
We know that, , for
If we take the supremum of both sides of (9) over we get the following
Due to () Definition 7, we get following
For multiplying both sides of (10) by we have
If we take the integral of both sides of (11) through we get
Hereby
We get the following result from the above inequality
Thus, the proof of Theorem 2 is completed. □
Theorem 3.
Let be positive increasing functions on . For , , we have
Proof.
The induction method will be used to prove our theorem. For , and , , we have
For and , , applying Theorem 1 we have
For we assume that the following inequality holds.
For we have to prove the following inequality
We know that is a positive increasing function. Thus, is a positive increasing function.
Let and applying Theorem 1 we have
and
Multiplying both sides of (12) by we have
Herewith, we get the following result from the above inequality
□
Theorem 4.
Let , . Suppose to be continuous on with . Then we have
Proof.
By Definition 6 we know that
Hence, by Hölder’s inequality, we have
Herewith, the following result is obtained
If we take the integral of both sides of (13) through we get
Now, we present a few applications of our results. □
4. Applications
Example 1.
Let , ; be two synchronous functions on . From Definition 3
and
Then, for , , we have
Example 2.
Let , ; be two synchronous functions on . Then , , , we have
Example 3.
Let ; be a synchronous function on . Then, for , , we have
Remark 1.
Let be a measurable function for . Using Definition 2, we can easily see that the following norm inequalities are provided in the variable exponential Lebesgue space.
- (I)
- (II)
- (III)
5. Discussion and Conclusions
Recently, the concept of inequalities and dynamic equations in time scales has gained an important place in the scientific literature. Mathematicians have emphasized many aspects of integral inequalities and integral equation, for example, transformations, inverse conversions, extensions, etc. However, these studies did not work on time scales. Moreover, the contribution of these studies to science has been weak. In particular, apart from the science of mathematics, we see very little the effect of the concept of time scales in different science fields. This study motivated us to find solutions to problems in these areas. In this paper, we examined fractional maximal integral inequalities on time scales. Furthermore, we demonstrated that different results can be obtained. These results can be examined in two or more dimensions. Moreover, they can be extended to nabla and diamond alpha derivatives.
Funding
This research received no external funding.
Acknowledgments
The author is grateful to the editor and the referees for their careful reading of the manuscript and their valuable comments.
Conflicts of Interest
The author declares no conflict of interest.
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