Abstract
This paper provides novel generalizations by considering the generalized conformable fractional integrals for reverse Copson’s type inequalities on time scales. The main results will be proved using a general algebraic inequality, chain rule, Hölder’s inequality, and integration by parts on fractional time scales. Our investigations unify and extend some continuous inequalities and their corresponding discrete analogues. In addition, when α = 1, we obtain some well-known time scale inequalities due to Hardy, Copson, Bennett, and Leindler inequalities.
MSC:
26A15; 26D10; 39A13; 34A40; 34N05
1. Introduction
The Hardy discrete inequality is known as (see []):
where .
In [], Hardy exemplified the continuous version of by utilizing the calculus of variations, which has the form:
where , which is integrable over is a convergent and integrable function over and is a sharp constant in and
In [,], Copson outreached the inequalities of Hardy and Particularly, he exemplified that if then:
and if then
The continuous transcriptions of and were exemplified by Copson in []. Particularly, he exemplified that if then:
where then
where .
Leindler in [] and Bennett in [] obtains some generalizations of and by using new weighted function. Specially, Leindler exemplified that if then:
Bennett explicated that if then:
Bennett in [,] established a converses of the inequalities and Particularly, he exemplified that if then:
and if then
where
In the last decades, the study of the dynamic equations and inequalities on time scales became a main field in applied and pure mathematics. We refer to the papers [,,,,,,]. In fact, Refs. [,,,,,,,,] mentions forms of the above inequalities on a time-scale and their extensions.
For example, in [], Saker et al. exemplified the time scale version of a converse of the inequalities and , respectively, as follows:
Assume that be a time scale with then
If , then
where
In the same paper [], Saker et al. proved the time scale transcript of the Bennet-Leindler inequalities and , respectively, as follows: Assume that is a time scale with . then:
If , such that
and , then
In recent years, a lot of work has been published on fractional inequalities and the subject has become an active field of research with several authors interested in proving the inequalities of fractional type by using the Riemann-Liouville and Caputo derivative (see [,,]).
On the other hand, the authors in [,] introduced a new fractional calculus called the conformable calculus and gave a new definition of the derivative with the base properties of the calculus based on the new definition of derivative and integrals.
The main question that arises now is: Is it possible to prove new fractional inequalities on timescales and give a unified approach of such studies? This in fact needs a new fractional calculus on timescales. Very recently Torres and others, in [,], combined a time scale calculus and conformable calculus and obtained the new fractional calculus on timescales. Thus, it is natural to look on new fractional inequalities on timescales and give an affirmative answer to the above question.
In particular, in this paper, we will prove the fractional forms of the classical Hardy, Copson type and its reversed and Leindler inequalities with employing conformable calculus on time scales. The article is structured as follows: Section 2 is an introduction of the basics of fractional calculus on timescales and Section 3 contains the main results.
2. Basic Concepts
In this part, we introduce the essentials of conformable fractional integral and derivative of order on time scales that will be used in this article (see [,,]). A time scale is an arbitrary nonempty closed subset of the real numbers . We define the operator , as . In addition, we define the function by Finally, for any , we refer to the notation .
In the following, we define conformable -fractional derivative and -fractional integral on .
Definition 1
(Definition 1, []). Suppose that Then for , we define to be the number with the property that, for any , there is a neighborhood V of s.t., we have:
The conformable -fractional derivative on at 0 as:
Theorem 1
(Theorem 51, []). Assume be conformable -fractional derivative on , then
- (i)
- The is conformable -fractional derivative and
- (ii)
- For , then -fractional differentiable and
- (iii)
- If v and are -fractional differentiable, then is a -fractionald differentiable and
- (iv)
- If v is -fractional differentiable, then is -fractional differentiable with:
- (v)
- If v and are -fractional differentiable, then is -fractional differentiable with:valid at all points for which .
Lemma 1
(Chain rule []). Suppose that is continuous and -fractional differentiable at , for and is continuously differentiable. Then is -fractional differentiable and
Definition 2
(Definition 26, []). For then the -fractional integral of , is defined as
Theorem 2
(Theorem 31, []). Suppose that . If , then
- (vi)
- (vii)
- (viii)
- (ix)
- (x)
Lemma 2
(Integration by parts formula []). Suppose that where . If are conformable -fractional differentiable and , then:
Lemma 3
(Hölder’s inequality []). Let where . If and , then
where and
Through our paper, we will consider the integrals are given exist (are finite i.e., convergent).
3. Results
Here, we will exemplify our main results in this article by utilizing Hölder’s inequality, chain rule, and integration by parts for fractional on time scale.
Theorem 3.
Suppose thatis a time scale with. Define
Then
Proof.
By utilizing the formula of integration by parts on
with and , we have
where
Using in , we see that
By utilizing chain rule, we get:
Since , we have
Next note . By the chain rule, we have (note )
This leads to
and then, we have
Substituting into yields:
Raises to the factor , we have:
By applying Hölder’s inequality on the term
with indices (note that ) and
we see that
This means that
by substitution into , we get
This means that
which the wanted inequality □
Corollary 1.
If we putin Theorem 6, then we get
where
which is in the Introduction.
Remark 1.
If we takein Theorem 6, then:
where
Remark 2.
Clearly, forRemark 1 coincides with Remark 1 in [].
Remark 3.
As a result, ifin (20),then:
where,
If , then becomes
where, which is Remark 2 in [].
Theorem 4.
Suppose thatbe a time scale with. Assume thatis defined as in Theorem 6 such that:
and define . Then
Proof.
Utilizing the formula of integration by parts on
with , we have
where . This with and implies that
But utilizing chain rule, we obtain:
Since we find that . By substituting into and using that , we get
Next note . By the chain rule, we have (note )
This implies that
By substituting (37) into (36) yields
Raising to the factor we get:
The rest of the proof is identical to the proof of Theorem and hence is deleted. □
Corollary 2.
If we putin Theorem, then:
where such that
which is in the Introduction
Remark 4.
If we takein Theorem, then
where
If then (41) becomes:
which is Remark in [].
Remark 5.
As a special case ofwhenwe get:
where
which is Remark in [], when
Theorem 5.
Suppose thatis a time scale with. Assume that. Then
Proof.
Utilizing the formula of integration by parts (18) on
with , we get
where . This with imply that
By utilizing chain rule, we get:
Since . By substituting into and using that , we have:
Next note . By the chain rule, we have (note )
This implies that
By substituting into yields
Raises to the factor h, we get:
The rest of the proof is identical to the proof of Theorem 6 and hence is deleted. □
Corollary 3.
If we putin Theorem, then:
where
which is in the Introduction.
Remark 6.
In Theorem 10, if we takethen:
where
If and , then becomes
where
which is Remark 5 in []
Remark 7.
As a special case ofwhen, we get:
where .
For in , then we get the inequality in Remark in [].
Theorem 6.
Suppose thatis a time scale withand. Assume thatsuch that
and define
Proof.
Utilizing the formula of integration by parts on
with , we have
where This with imply that
By utilizing chain rule, we obtain:
Since . By substituting into and using that , we have:
Next note . By the chain rule, we have (note )
And
by substituting (60) into (59), we get
Raises to the factor , we get
The rest of the proof is identical to the proof Theorem 6 and hence is deleted. □
Corollary 4.
If we putin Theorem, then:
where
which is in the Introduction
Remark 8.
If we takein Theorem, then:
where
If then (63) becomes
where
which is Remark 7 in []
Remark 9.
As a special case of, whenwe get:
where,
which is Remark in [], when
Applications
The applications of quantum calculus play an important role in mathematics and the field of natural sciences, such as physics and chemistry. It has many applications in orthogonal polynomials, number theory, quantum theory, etc. In this section, some example for Reverse Coposn’s Inequalities in fractional quantum calculus are selected to fulfil the applicability of the obtained results.
Now, we give an example using the time scale which is a time scale with interesting applications in quantum calculus.
Example 1.
(Quantum calculus case 1.): Let. Then for allwe have
Now, with the help of Theorem and the above identities in we can deduce
where,
and
For an application of Theorem , we give the following example.
Example 2.
(Quantum calculus case 2.): Letthen the relationis satisfy. Hence, we have:
Now, with the help of Theorem and the above identities in we can deduce:
where, is defined in the above example.
Note that. By using theorems 10 and 12, we can apply the technique used in the above examples to obtain different applications. In addition, the above result is important not only for arbitrary time scales, but also for quantum calculus.
4. Conclusions and Future Work
The new fractional calculus on timescales is presented with applications in new fractional inequalities on timescales like Hardy, Bennett, Copson, and Leindler types. Inequalities are considered in rather general forms and contain several special integral and discrete inequalities. The technique is based on the applications of well-known inequalities and new tools from fractional calculus. In future research, we will continue to generalize more dynamic inequalities by using Specht’s ratio, Kantorovich’s ratio, functional generalization, and n-tuple fractional diamond- α integral. It will be interesting to find the inequalities in α,β-symmetric quantum and stochastic calculus.
Author Contributions
M.Z. and H.M.R. contributed by preparing the introduction, preliminaries, and formulating (theorem 6, theorem 8) its proof and corollaries (cor.7, cor. 9 and cor.10). M.A. contributed by preparing the introduction, preliminaries, and formulating (theorem 10) its proof and corollaries (cor.11). G.A. contributed by preparing the introduction, preliminaries, and formulating theorem 12, its proof and corollaries (cor.7). C.C. and H.A.A.E.-H. contributed by preparing the introduction, preliminaries, and formulating theorem 6, its proof and corollaries (cor. 13). All authors contributed equally to the writing of the manuscript. All authors have read and agreed to the published version of the manuscript.
Funding
The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through the General Research Project, grant number GRP/56/42.
Data Availability Statement
No data were used to support this study.
Acknowledgments
The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through the General Research Project, grant number GRP/56/42.
Conflicts of Interest
The authors declare no conflict of interest.
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