1. Introduction
The theory of convex analysis offers robust ideas and methodologies to address an extensive spectrum of issues in applied sciences. Numerous mathematicians and researchers have been striving to implement innovative ideas of convexity theory to handle the real world problems arising in nonlinear programming, statistics, control theory, optimization, etc. The theory of convexity also plays a leading role in establishing a wide class of inequalities. The theory of inequalities in the framework of fractional operators gives rise to integral inequalities. The Ostrowski-type inequalities have been developed in the literature for various types of convex functions. Ostrowski derived the following remarkable and amazing integral inequality in 1938.
Theorem 1 ([
1])
. Let be a differentiable function in the interior of and let with If for all then∀
In the above famous integral inequality the constant value is an amazing choice in the aspect that it cannot be substituted by a smaller one. The Ostrowski-type inequality is found to be an exalted and applicable tool in several branches of mathematics. Integral inequalities, which are used to determine the bounds of physical quantities, find extensive applications in operator theory, statistics, probability theory, numerical integration, nonlinear analysis, information theory, stochastic analysis, approximation theory, biological sciences, physics and technology. Many researchers have shown a keen interest in developing several variants and aspects of this inequality.
During the past few decades, fractional calculus has evolved as a fast-emerging and prominent area of investigation due to the nonlocal nature of fractional order integral and derivative operators. The tools of fractional calculus have been widely applied to formulate the mathematical models associated with various phenomena and processes occurring in engineering and scientific disciplines. The importance and applications of fractional calculus are eminent in the related literature. In the realm of inequalities, fractional order operators have played a fundamental role in the advancement of the topic. In particular, fractional integral operators are found to be of exceptional value in generalizing the standard integral inequalities. Here, we recall that certain inequalities are quite helpful in investigating optimization problems.
The main aim of this manuscript is to present an up-to-date review of Ostrowski-type inequalities involving different convexities and fractional integral operators. In each section/subsection of the paper, we first describe the fractional integral operators and convexities, related to the results collected for Ostrowski-type fractional integral inequalities. We provide comprehensive details for each Ostrowski-type inequality collected in this survey (without proof) for the convenience of the reader. Our survey paper contains the state-of-the-art literature review on fractional Ostrowski-type inequalities and serves as an excellent platform for the researchers who wish to initiate/develop new work on such inequalities.
The structure of this review paper is designed as follows.
Section 2 summarizes Ostrowski-type fractional integral inequalities for different families of convexities, including classical convex functions, quasi-convex functions,
-convex functions,
s-convex functions,
-convex functions, strongly convex functions, harmonically convex functions,
h-convex functions, Godunova-Levin-convex functions,
-convex functions,
P-convex,
m-convex functions,
-convex functions, exponentially
s-convex functions,
-convex functions, exponential-convex functions,
-convex functions, quasi-geometrically convex functions,
-convex functions and
n-polynomial exponentially
s-convex functions.
Section 3 consists of Ostrowski-type fractional integral inequalities for Katugampola fractional integral operators. In
Section 4, we present Ostrowski-type fractional integral inequalities involving
k-Riemann–Liouville fractional integrals.
Section 5 is concerned with Ostrowski-type fractional integral inequalities for preinvex functions, while Ostrowski-type fractional integral inequalities involving fractional integrals with respect to another function are described in
Section 6. Mercer-Ostrowski-type fractional integral inequalities for Riemann–Liouville fractional integral operators are included in
Section 7. Ostrowski-type fractional integral inequalities obtained via Hadamard fractional integral are discussed in
Section 8. We collect Ostrowski-type fractional integral inequalities for integrals with exponential kernel function in
Section 9.
Section 10 deals with Ostrowski-type fractional integral inequalities for Atangana-Baleanu-type fractional integral operators, while
Section 11 contains Ostrowski-type inequalities in terms of generalized fractional integral operators. In
Section 12, we discuss Ostrowski-type fractional integral inequalities obtained via operators of quantum-calculus and Ostrowski-type inequalities of tensorial type are presented in
Section 13.
2. Ostrowski-Type Inequalities via Riemann–Liouville Fractional Integral
First, we add the definitions of fractional operators, namely Riemann–Liouville, in the left and right aspects.
Definition 1 ([
2])
. Let Then, the Riemann–Liouville integrals (left and right aspect) and are stated byandrespectively. Here, represent the Euler Gamma function and 2.1. Ostrowski-Type Fractional Integral Inequalities for Functions with Bounded Derivative
In this subsection, we present results on Ostrowski-type fractional integral inequalities for functions with bounded derivatives. We have the following results that provide lower and upper bounds for the Ostrowski differences.
Theorem 2 ([
3])
. Let be a differentiable mapping on and for all Thenfor all and Theorem 3 ([
3])
. Let the assumptions of this theorem be as stated in Theorem 2 and with . Then∀
and where Theorem 4 ([
4])
. Let the assumptions of this theorem be as stated in Theorem 2. Thenfor all and Theorem 5 ([
4])
. Let the assumptions of this theorem be as stated in Theorem 2 and If for all thenfor all and whereand In the next result, fractional integral inequalities of Ostrowski-Grüss type are presented.
Theorem 6 ([
5])
. Suppose is a differentiable function and with If is bounded on with for all thenfor all and where Now we give one more Ostrowski-Grüss-type inequality of fractional type.
Theorem 7 ([
6])
. Let the assumptions of this theorem be stated in Theorem 2. Thenwhere 2.2. Ostrowski-Type Fractional Integral Inequalities for Convex Functions
Definition 2 ([
7])
. A real-valued function Π is convex on an interval I, ifholds for all and In the following theorems, we show the Ostrowski-type inequalities in the frame of Riemann–Liouville fractional integrals for absolutely continuous and convex functions.
Theorem 8 ([
8])
. Let be an absolutely continuous function on If and there exist real numbers such thatandThenand Theorem 9 ([
8])
. Let be a convex function and Thenandwhere are the lateral derivatives of Theorem 10 ([
9])
. Let be a function which is differentiable on with such that If is convex on and then Theorem 11 ([
9])
. Let Π be as in Theorem 10. If is convex on , and thenwhere and Theorem 12 ([
9])
. Let Π be as in Theorem 10. If is convex on , and then Theorem 13 ([
9])
. Let Π be as in Theorem 10. If is convex on , and then Now we give some weighted fractional Ostrowski-type integral inequalities.
Theorem 14 ([
10])
. Let be a function which is differentiable on with and If is continuous and is convex on thenfor all where Theorem 15 ([
10])
. Let Π and g be as in Theorem 14. If is convex on thenfor all where 2.3. Ostrowski-Type Fractional Integral Inequalities for Quasi-Convex Functions
Definition 3 ([
11])
. A real-valued Π is quasi-convex, ifholds for all and In the following theorems, we explore some weighted Ostrowski-type inequalities in the frame of fractional operator for quasi-convex functions.
Theorem 16 ([
12])
. Let be a function which is differentiable on where and be a continuous function. If is quasi-convex, thenfor all Theorem 17 ([
12])
. Let Π be as in Theorem 16. If is quasi-convex, and thenfor all Theorem 18 ([
12])
. Let Π be as in Theorem 16. If is quasi-convex, thenfor all A further result for functions with a bounded first derivative is given in the next theorem.
Theorem 19 ([
12])
. Let the assumptions of this theorem be as stated in Theorem 16. If there exist constants such that for all thenwhere Definition 4 ([
13])
. A function is said to be a strongly quasi-convex function with modulus if The aim of this subsection is to give some Ostrowski-type fractional integral inequalities for strongly quasi-convex functions.
Theorem 20 ([
14])
. Let be a differentiable mapping on such that If is a strongly quasi-convex function with modulus on thenfor each Theorem 21 ([
14])
. Let Π be as in Theorem 20. If is a strongly quasi-convex function with modulus on thenfor each and Theorem 22 ([
14])
. Let Π be as in Theorem 20. If is a strongly quasi-convex function with modulus on thenfor each In the next, we present fractional weighted Ostrowski-type fractional integral inequalities via a strongly quasi-convex function.
Theorem 23 ([
14])
. Let Π be as in Theorem 20 and be a continuous function. If is a strongly quasi-convex function with modulus on thenfor each Theorem 24 ([
14])
. Let Π be as in Theorem 20 and be a continuous function. If is a strongly quasi-convex function with modulus and thenfor each 2.4. Ostrowski-Type Fractional Integral Inequalities for -Convex Functions
Definition 5 ([
15])
. The function is said to be -convex, iffor all and Ostrowski-type fractional integral inequalities pertaining to Riemann–Liouville fractional integral for -convex functions are presented in the following theorems.
Theorem 25 ([
16])
. Let I be an open real interval such that and be a differentiable mapping on I such that where with If is -convex on for and thenfor all Theorem 26 ([
16])
. Let Π be as in Theorem 25. If is -convex on for and thenwith and Theorem 27 ([
16])
. Let Π be as in Theorem 25. If is -convex on for and thenfor all 2.5. Ostrowski-Type Fractional Integral Inequalities for s-Convex Functions
Definition 6 ([
17])
. A function is said to be s-convex in the second sense, ifholds for all and for some fixed Ostrowski-type inequalities pertaining to Riemann–Liouville fractional integral for s-convex functions are presented.
Theorem 28 ([
18])
. Let be a function which is differentiable on with such that Suppose is s-convex in the second sense on for and Then, for all Theorem 29 ([
18])
. Let Π be as in Theorem 28. If is s-convex in the second sense on for and thenwhere and Theorem 30 ([
18])
. Let Π be as in Theorem 28. If is s-convex in the second sense on for and thenfor all with Theorem 31 ([
19])
. Let Π be as in Theorem 28. If thenfor all Theorem 32 ([
19])
. Let Π be as in Theorem 28. If is s-convex in the second sense on for and thenfor all Theorem 33 ([
19])
. Let Π be as in Theorem 28. If is s-convex in the second sense on for and thenfor all 2.6. Ostrowski-Type Fractional Integral Inequalities for -Convex Functions
Definition 7 ([
20])
. A function is said to be -convex in mixed kind, ifholds for all and Now, we state the generalization of the classical Ostrowski inequality via fractional integrals, which is obtained for -convex function in mixed kind.
Theorem 34 ([
20])
. Let be a function which is differentiable on with and If is -convex on and thenfor all Theorem 35 ([
20])
. Let Π be as in Theorem 34. If is -convex on and thenfor all Theorem 36 ([
20])
. Let Π be as in Theorem 34. If be -convex on and thenfor all and 2.7. Ostrowski-Type Fractional Integral Inequalities for Harmonically-Convex Functions
Definition 8 ([
21])
. Let be a real interval. A function is harmonically convex, iffor all and Some new Ostrowski’s-type fractional integral inequalities for functions whose first derivatives are harmonically convex, via Riemann–Liouville fractional integrals are given in the next theorems.
Theorem 37 ([
22])
. Let be a differentiable mapping on with such that If is harmonically convex on then, for all wherewith the hypergeometric function and Theorem 38 ([
22])
. Let be a differentiable mapping on with such that If is harmonically convex on where and then, for all 2.8. Ostrowski-Type Fractional Integral Inequalities for h-Convex Functions
Definition 9 ([
23])
. Suppose h is a non-negative and real-valued function. Then is an h-convex, if Π is non-negative and for all we have Some Ostrowski-type inequalities via Riemann–Liouville fractional integrals for h-convex are given in the next theorems.
Theorem 39 ([
24])
. Let be a function which is differentiable on with such that . If is h-convex on and thenfor each Theorem 40 ([
24])
. Let Π be as in the Theorem 39. If is h-convex on , thenfor each Theorem 41 ([
24])
. Let Π be as in the Theorem 39. If is h-convex on thenfor each Ostrowski-type fractional integral inequalities for super-multiplicative functions pertaining to Riemann–Liouville fractional integrals are given now.
Definition 10 ([
25])
. We say that is a super-multiplicative function, if for all one has Theorem 42 ([
26])
. Let be a super-multiplicative and non-negative function, for be a differentiable function on with such that If is a h-convex function on and then for and we have: Theorem 43 ([
26])
. Let Π be as in Theorem 42. If is a h-convex function on and then for and we have: Theorem 44 ([
26])
. Let Π be as in Theorem 42. If is a h-convex function on and then for and we have: 2.9. Ostrowski-Type Fractional Integral Inequalities for Godunova-Levin Functions
Definition 11 ([
27])
. A function is a Godunova–Levin function iffor all and Definition 12 ([
28])
. A function is an s-Godunova-Levin function of the first kind, where iffor all and Definition 13 ([
28])
. A function is said to be an s-Godunova-Levin function of the second kind, where iffor all and In this subsection, we show some Ostrowski-type inequalities pertaining to Riemann–Liouville fractional integrals for s-Godunova-Levin functions.
Theorem 45 ([
29])
. Suppose is a differentiable function on with and If is an s-Godunova-Levin function of the second kind on and thenfor all Theorem 46 ([
29])
. Let Π be as in Theorem 45. If is an s-Godunova-Levin function of the second kind on and then:for all Now, we present some new family of s-Godunova-Levin functions, which are called -Godunova-Levin functions of the second kind. Next, we present some new Ostrowski-type integral inequalities for -Godunova-Levin functions via fractional integrals.
Definition 14 ([
30])
. A function is said to be an -Godunova-Levin function of the second kind, where iffor all and Theorem 47 ([
30])
. Suppose is a differentiable function on open interval with such that If is an -Godunova-Levin function of the second kind on and then, for all where Theorem 48 ([
30])
. Let Π be as in Theorem 47. Then, for all where Theorem 49 ([
30])
. Let the assumptions of this theorem be stated in Theorem 47. Then, for all where 2.10. Ostrowski-Type Fractional Integral Inequalities for -Convex Function
Definition 15 ([
31])
. A real-valued and non-negative function Π is -convex function, iffor all and . In this subsection, we give some Ostrowski-type fractional integral inequalities for -convex functions via Riemann–Liouville fractional integrals.
Theorem 50 ([
32])
. Suppose is a mapping which is differentiable on with such that If is MT-convex function on and then for and we have: Theorem 51 ([
32])
. Let Π be as in Theorem 50. If is MT-convex function on and then for and we have: Theorem 52 ([
32])
. Let Π be as in Theorem 50. If is MT-convex function on and then for and we have: Theorem 53 ([
33])
. Let the assumptions of this theorem be stated in Theorem 50. Then for and we have: Theorem 54 ([
33])
. Let Π be as in Theorem 50. If is MT-convex function on and then for and we have: Theorem 55 ([
34])
. Let the assumptions of this theorem be stated in Theorem 50. Then for and we have:whereand the incomplete Beta function. Theorem 56 ([
34])
. Let Π be as in Theorem 50. If is MT-convex function on and then for and we have:where Theorem 57 ([
34])
. Let Π be as in Theorem 50. If is MT-convex function on and then for and we have:where is given in Theorem 55. 2.11. Ostrowski-Type Fractional Integral Inequalities for P-Convex, m-Convex and -Convex Functions
In this subsection, we show results on Ostrowski-type fractional integral inequalities for twice differentiable functions and different kinds of convexity.
Definition 16 ([
35])
. The function is said to be P-convex, if is nonnegative and∀
and Definition 17 ([
36])
. A real-valued function Π is m-convex, if∀
and Definition 18 ([
15])
. A real-valued function Π is -convex, if∀
and Theorem 58 ([
37])
. Let be a twice differentiable function on such that where with If is a convex function on and is bounded, i.e., for any then Theorem 59 ([
37])
. Let Π be as in Theorem 58. If is a P-convex function on and is bounded, i.e., for any then Theorem 60 ([
37])
. Let Π be as in Theorem 58. If is s-convex on and is bounded, i.e., for any then Theorem 61 ([
37])
. Let Π be as in Theorem 58. If is h-convex on and is bounded, i.e., for any then Theorem 62 ([
37])
. Let Π be as in Theorem 58. If is m-convex on and is bounded, i.e., for any then Theorem 63 ([
37])
. Let Π be as in Theorem 58. If is -convex on and is bounded, i.e., for any then 2.12. Ostrowski-Type Fractional Integral Inequalities for n-Polynomial Exponentially s-Convex Functions
Now, we present some Ostrowski-type inequalities for differentiable exponentially s-convex functions.
Definition 19 ([
38])
. Let Then the real-valued function Π is an exponentially s-convex function if∀
and Theorem 64 ([
38])
. Let be a differentiable mapping on with If is an exponentially s-convex function on for some and , for all thenfor all Theorem 65 ([
38])
. Let be a differentiable function on with If is an exponentially s-convex function on for some and , for all thenfor all Theorem 66 ([
38])
. Let be a differentiable function on with If is an exponentially s-convex function on for some and , for all thenfor all Some enhancements of the Ostrowski-type inequality for differentiable n-polynomial exponentially s-convex functions are presented in the next theorems.
Definition 20 ([
39])
. Let and Then is an n-polynomial exponentially s-convex function iffor all and Theorem 67 ([
39])
. Let be a differentiable mapping on with If is an n-polynomial exponentially s-convex function on for some and , for all thenfor all Theorem 68 ([
39])
. Let Π be as in Theorem 67. If is an n-polynomial exponentially s-convex function on for some and and , for all then:for all Theorem 69 ([
39])
. Let Π be as in Theorem 67. If is an n-polynomial exponentially s-convex function on for some and , for all thenfor all Theorem 70 ([
40])
. Let the assumptions of this theorem be stated in Theorem 67. Thenfor all Theorem 71 ([
40])
. Let Π be as in Theorem 67. If is an n-polynomial exponentially s-convex function on for some and and , for all then:for all Theorem 72 ([
40])
. Let Π be as in Theorem 67. If is an n-polynomial exponentially s-convex function on for some and , for all then:for all 3. Ostrowski-Type Inequalities for Katugampola Fractional Integral Operator
Here, we present some Ostrowski-type inequalities via the Katugampola fractional integral operator.
Definition 21 ([
41])
. Let be a finite interval. Then, the left- and right-side Katugampola fractional integral of order of are defined bywith and if the integrals exist. Here, denote the space of those complex-valued Lebesque measurable functions Π on for which where for and if Theorem 73 ([
42])
. Let be a differentiable function on with such that If is h-convex on and thenwith and Theorem 74 ([
42])
. Let Π be as in Theorem 73. If is h-convex on and then:with and Theorem 75 ([
42])
. Let Π be as in Theorem 73. If is h-convex on and then:with and Some Ostrowski-type inequalities pertaining to Katugampola fractional integral for s-Godunova-Levin functions are presented.
Theorem 76 ([
43])
. Let be a function which is differentiable on with such that If is an s-Godunova-Levin function of the second kind on and then:with and Theorem 77 ([
43])
. Let Π be as in Theorem 76. If is an s-Godunova-Levin function of the second kind on and then:with and Theorem 78 ([
43])
. Let Π be as in Theorem 76. If is an s-Godunova-Levin function of the second kind on and thenwith and Theorem 79 ([
43])
. Let the assumptions of this theorem be as stated in Theorem 76. Then:with and Theorem 80 ([
43])
. Let Π be as in Theorem 76. If is an s-Godunova-Levin function of the second kind on and then:with and Using -convex function with the aid of Katugampola fractional integral, some Ostrowski-type inequalities are obtained, which are given in the next theorems.
Theorem 81 ([
44])
. Suppose is a differentiable function on I such that where with If is -convex on and thenwith and Theorem 82 ([
44])
. Let Π be as in Theorem 81. If is -convex on and then:with and Theorem 83 ([
44])
. Let Π be as in Theorem 81. If is -convex on and then:with and Theorem 84 ([
44])
. Let Π be as in Theorem 81. If is -convex on and then:with Theorem 85 ([
44])
. Let Π be as in Theorem 81. If is -convex on and then:with and We continue by giving some Ostrowski-type inequalities for p-convex functions pertaining to the Katugampola fractional integral.
Definition 22 ([
45])
. A function is p-convex, if∀
and Theorem 86 ([
46])
. Let be a function which is differentiable on with such that Let be a p-convex function, and .If , then If then we have:
Theorem 87 ([
46])
. Let Π be as in Theorem 86. Let be a p-convex function, and If , then
Theorem 88 ([
46])
. Let the assumptions of this theorem be as stated in Theorem 87, and such that Suppose , then Suppose , then
Theorem 89 ([
46])
. Let the assumptions of this theorem be as stated in Theorem 86 and such that .Suppose , then
Theorem 90 ([
47])
. Let be a differentiable mapping on and with such that If is p-convex on I and for all (if otherwise ), thenwhereand and is the hypergeometric function. Theorem 91 ([
47])
. Let Π be as in Theorem 90. If is p-convex on I and for all thenwhereand and Theorem 92 ([
47])
. Let Π be as in Theorem 90. If is p-convex on I and for all (if otherwise ), thenwhereand 4. Ostrowski-Type Fractional Integral Inequalities via -Riemann–Liouville Fractional Integral
Definition 23 ([
48])
. Let and The k-Riemann–Liouville fractional integrals and of order for a real-valued function Π are defined byandrespectively, where is the k-Gamma function We present some Ostrowski-type inequalities for s-Godunova-Levin of a second kind via the Riemann–Liouville k-fractional integral.
Theorem 93 ([
49])
. Let be a function which is differentiable on with such that If is an s-Godunova-Levin function of the second kind on and then, for all Theorem 94 ([
49])
. Let Π be as in Theorem 93. If is an s-Godunova-Levin function of the second kind on and then, for all with Theorem 95 ([
49])
. Let Π be as in Theorem 93. If is an s-Godunova-Levin function of the second kind on and then, for all Theorem 96 ([
49])
. Let the assumptions of this theorem be stated in Theorem 93. Then, for all Here, utilizing strongly -convex via the k-Riemann–Liouville fractional integral, some Ostrowski-type inequalities are presented.
Definition 24 ([
50])
. A real-valued function is strongly -convex, iffor all and Theorem 97 ([
50])
. Let be a differentiable function on such that with If is strongly -convex with modulus for and thenfor all and Theorem 98 ([
50])
. Let Π be as in Theorem 97. If is strongly -convex with modulus for and then:for all and Theorem 99 ([
50])
. Let Π be as in Theorem 97. If is strongly -convex with modulus for and then:for all and Here, we add some Ostrowski-type inequalities for exponentially convex functions via the k-Riemann–Liouville fractional integral.
Definition 25 ([
51])
. A function is said to be an exponential-convex function, iffor all and all Theorem 100 ([
52])
. Let be a differentiable mapping on If Π is an exponential-convex function, thenif and for all Theorem 101 ([
52])
. Let be a function which is differentiable on and be a strictly increasing function such that and for all If Π is an exponential-convex function, the following inequalities for k-fractional integrals hold:andfor all Ostrowski-type fractional integral inequalities via k-fractional integral, which are obtained for -convex in mixed kind, are presented in the next theorems.
Theorem 102 ([
53])
. Let be a function which is absolutely continuous and If is an -convex function on and then for and we have: Theorem 103 ([
53])
. Let be an absolutely continuous function and If is an -convex function on and then for and we have: Theorem 104 ([
53])
. Let be an absolutely continuous function and If with is an -convex function on and then for and we have: Here, we add some fractional Ostrowski-type inequalities via -convex functions.
Theorem 105 ([
54])
. Let be a differentiable mapping on with such that If is an -convex function on and then for and we have: Theorem 106 ([
54])
. Let Π be as in Theorem 105. If is an -convex function on and then for and we have: Theorem 107 ([
54])
. Let Π be as in Theorem 105. If is an -convex function on and then for and we have: 5. Ostrowski-Type Fractional Integral Inequalities for Preinvex Functions
Definition 26 ([
55])
. A set is invex w.r.t if ∀ we have Definition 27 ([
55])
. A function is preinvex w.r.t. η if∀
and all Definition 28 ([
56])
. The nonnegative function Π on the invex set K is prequasi invex w.r.t. iffor all and Condition C. [
57]
Suppose be an invex subset w.r.t. We say that the function η satisfies the condition C if for any and Ostrowski-type inequalities for preinvex and prequasiinvex functions are given in the next theorems.
Theorem 108 ([
58])
. Let be an open invex subset with respect to and with Suppose that is a differentiable function. If Π is integrable on and is a preinvex function on thenfor all Theorem 109 ([
58])
. Let Π be as in Theorem 108. If Π is integrable on and is a preinvex function on and η satisfies condition C, thenfor all where Theorem 110 ([
58])
. Let the assumptions of this theorem be as stated in Theorem 108. If is integrable on and is a prequasiinvex function on thenfor all Theorem 111 ([
58])
. Let the assumptions of this theorem be stated in Theorem 108. If is integrable on and is a prequasiinvex function on η satisfies condition thenfor all where Theorem 112 ([
59])
. Let be a differentiable mapping such that and If is a prequasiinvex function, thenfor all Theorem 113 ([
59])
. Let the assumptions of this theorem be as stated in Theorem 112. If is a prequasiinvex function, where thenfor all In the next, we develop some fractional Ostrowski-type inequalities for twice differentiable preinvex mappings.
Theorem 114 ([
60])
. Suppose that is a twice differentiable mapping with If and is preinvex in then for all Theorem 115 ([
60])
. Suppose that is a twice differentiable mapping with If and is preinvex in then, for all where Theorem 116 ([
60])
. Suppose that is a function which is twice differentiable with If and is preinvex in then, for all Definition 29 ([
61])
. A function is s-preinvex in the second aspect w.r.t. η for some iffor all and all Some Ostrowski-type inequalities for s-preinvex in the second sense, are given in the next theorems.
Theorem 117 ([
62])
. Let be a differentiable function such that and If is s-preinvex, for thenfor all Theorem 118 ([
62])
. Let Π be as in Theorem 117. If is s-preinvex, for some fixed with thenfor all Theorem 119 ([
62])
. Let Π be as in Theorem 117. If is s-preinvex for some fixed Thenfor all Definition 30 ([
63])
. A non-negative function is -preinvex w.r.t. iffor all and all Here, we add some Ostrowski-type inequalities involving -preinvex via Reimann-Liouville integral operators.
Theorem 120 ([
64])
. Suppose be a differentiable mapping such that and If is -preinvex, thenfor all Theorem 121 ([
64])
. Let be a differentiable function such that and If is -preinvex, with thenfor all Theorem 122 ([
64])
. Let be a differentiable mapping such that and If is -preinvex, thenfor all 6. Ostrowski-Type Fractional Integral Inequalities via Riemann–Liouville Fractional Integrals of a Function with Respect to Another Function
In this section, we add some fractional Ostrowski-type inequalities w.r.t. another function.
Definition 31 ([
2,
65])
. Let be the interval of and Suppose is a positive monotone and increasing function on having on The ψ-Riemann–Liouville fractional integrals of a function (left and right sided) g w.r.t. another function ψ on are defined byrespectively. We start with Ostrowski-type fractional inequalities involving fractional integrals with respect to another function and h-convex functions.
Theorem 123 ([
66])
. Let be a function which is differentiable on with is integrable on Additionally, let be h-convex on and Then, for all Theorem 124 ([
66])
. Let Π be as in Theorem 123. Additionally, let be h-convex on and Then, for all where Theorem 125 ([
66])
. Let Π be as in Theorem 123. Additionally, let be h-convex on and Then, for all Theorem 126 ([
66])
. Let Π be as in Theorem 123. Additionally, let be h-convex on and Then, for all where Now, we add some Ostrowski-type inequalities via fractional integrals with respect to another function, i.e., -convex functions in mixed kind, according to the following definition.
Definition 32 ([
67])
. Let The function is -convex function, iffor all and Theorem 127 ([
67])
. Let be a function which is differentiable on with and is integrable on Additionally, let be a -convex function on and for all ψ is a Lipschizian function. Thenfor all Theorem 128 ([
67])
. Let Π be as in Theorem 127. Additionally, let be a -convex function on and for all ψ is a Lipschizian function. Thenfor all Theorem 129 ([
67])
. Let Π be as in Theorem 127. Additionally, let be a -convex function on such that and for all ψ is a Lipschizian function. Thenfor all Here, we add some fractional Ostrowski-type inequalities for functions with respect to another function.
Theorem 130 ([
68])
. Let be a mapping differentiable on and and for all Suppose is positive monotone and increasing, and for all Let and be the left- and right-Riemmansided fractional integrals. Thenwhere and Theorem 131 ([
68])
. Assume that Π and ψ are as in Theorem 130. If for all and all thenandwhere and Theorem 132 ([
68])
. Assume that Π and ψ are as in Theorem 130. Thenwhere and 7. Mercer-Ostrowski-Type Fractional Integral Inequalities for Riemann–Liouville Fractional Integral Operator
In this section, we present Mercer-Ostrowski-type fractional integral inequalities for first order differentiable functions for the Riemann–Liouville integral operator.
Theorem 133 ([
69])
. Let be a differentiable function on with such that If is a convex function on then Theorem 134 ([
69])
. Let Π be as in Theorem 133. If is a convex function on thenwhere Theorem 135 ([
69])
. Let Π be as in Theorem 133. If is a convex function on then Throughout this portion, Mercer-Ostrowski-type inequalities for differentiable functions via -Riemann–Liouville fractional integral operators are obtained.
Theorem 136 ([
70])
. Let be a function which is differentiable on with be integrable on Let be an increasing and positive monotone function on having a continuous derivative on If is a convex function on then for and we have: Theorem 137 ([
70])
. Assume that Π and ψ are as in Theorem 136. If is a convex function on then for and we have:where and Theorem 138 ([
70])
. Assume that Π and ψ are as in Theorem 136. If is a convex function on then for and we have: 8. Ostrowski-Type Fractional Integral Inequalities via Hadamard Fractional Integral
Definition 33 ([
2])
. Hadamard fractional integrals (left and right) of order of function Π are defined byand Definition 34 ([
71])
. The function is called quasi-geometrically convex on I iffor all and Fractional Ostrowski-type fractional integral inequalities for functions which are differentiable and quasi-geometrically convex, are given now.
Theorem 139 ([
72])
. Let be a differentiable mapping on with Let be a continuous, positive and geometrically symmetric to and If is quasi-geometrically convex, then, for all Theorem 140 ([
72])
. Let be a differentiable mapping on with Let be a continuous, positive and geometrically symmetric to and If is quasi-geometrically convex, and thenfor all Theorem 141 ([
72])
. Let be a differentiable mapping on with Let be a continuous, positive and geometrically symmetric to and If is quasi-geometrically convex, then, for all Definition 35 ([
73])
. A function is said to satisfy the -condition iffor all and for some fixed Here, we add some fractional Ostrowski inequalities for -condition.
Theorem 142 ([
73])
. Let be a function which is differentiable on with such that If satisfies the -condition on for and thenfor all Theorem 143 ([
73])
. Let Π be as in Theorem 142. If satisfies the -condition on for and thenfor all where Theorem 144 ([
73])
. Let the assumptions of this theorem be stated in Theorem 143. Thenfor all where 9. Ostrowski-Type Fractional Integral Inequalities for Exponential Kernel
Here, in this section, we add some Ostrowski-type inequalities for exponential kernel.
Definition 36 ([
74])
. Let The left and right fractional integrals of order are defined byandrespectively. Theorem 145 ([
75])
. Let be a function which is differentiable with and If is a convex function on then, for all where and Theorem 146 ([
75])
. Let be a function which is differentiable with and If is a convex function on thenfor all where defined in the previous theorem. 10. Ostrowski-Type Fractional Integral Inequalities via Atangana-Baleanu Fractional Integrals Operator
In this section, we give Ostrowski-type fractional integral inequalities for Atangana-Baleanu fractional integral operator for twice differentiable functions.
Definition 37 ([
76])
. The left and right Atangana-Baleanu fractional integrals operators with nonlocal kernel of a function are defined asfor and a normalization function satisfying Theorem 147 ([
77])
. Let be a differentiable mapping on such that If is a convex on , then ∀ the inequality is given as Theorem 148 ([
77])
. Let be a differentiable mapping on such that If is a convex on , then ∀ the inequality is given as:where and Theorem 149 ([
78])
. Let be a twice differentiable mapping on with such that If is a convex function on , then for all the inequality is given as:for all Theorem 150 ([
78])
. Let be a twice differentiable mapping on with such that If is a convex function on , then for all the inequality is given as:for all where Theorem 151 ([
78])
. Let be a twice differentiable mapping on with such that If is a convex on , then ∀ the inequality is given as:for all Now, we give Ostrowski-type fractional integral inequalities for Atangana-Baleanu fractional integral operators for twice differentiable s-convex functions.
Theorem 152 ([
79])
. Let be a twice differentiable mapping on with such that If is s-convex in the second sense on for then, for all Theorem 153 ([
79])
. Let Π be as in Theorem 152. If is s-convex in the second sense on for then, for all where Theorem 154 ([
79])
. Let Π be as in Theorem 152. If is s-convex in the second sense on for then, for all Theorem 155 ([
80])
. Let be a differentiable mapping on with such that If is an s-convex function in the second sense on and for all for some fixed then, for all Theorem 156 ([
80])
. Let Π be as in Theorem 155. If is an s-convex function in the second sense on and for all for some fixed thenfor all where and Theorem 157 ([
80])
. Let the assumptions of this theorem be as stated in Theorem 156. Thenfor all We will give now results on Ostrowski-type fractional integral inequalities containing second order derivatives for s-convex functions in the second sense.
Theorem 158 ([
80])
. Let be a differentiable mapping on with such that If is s-convex in the second sense on for then, for all Theorem 159 ([
80])
. Let Π be as in Theorem 158. If is s-convex in the second sense on for thenfor all where and 11. Ostrowski-Type Fractional Integral Inequalities via Generalized Fractional Integrals
We define the left and right sided generalized fractional integrals as:
Definition 38 ([
81])
. The left and right-sided generalized fractional integrals given as follows:where the function satisfies Some inequalities connected with the Ostrowski-type inequality using of generalized fractional integral operators are presented now.
Theorem 160 ([
82])
. Let be a differentiable mapping on and for all Then, for all where is the Peano kernel function. Theorem 161 ([
82])
. Suppose be a function which is differentiable on and for all and Thenfor all where is the Peano kernel function defined in previous theorem. In the following, we present some Ostrowski-type inequalities for differentiable harmonically convex functions via the generalized fractional integrals.
Theorem 162 ([
83])
. Let be a differentiable mapping on such that If is harmonically convex on for some , then for all where the mappings Δ and Λ are defined as:and Theorem 163 ([
83])
. Let be a differentiable mapping on such that If is harmonically convex on for some , then, for all where and 12. Ostrowski-Type Fractional Integral Inequalities via Quantum Calculus
Definition 39 ([
84])
. Let function be continuous. Thenis called -derivative of Π at Definition 40 ([
84])
. Let function be continuous. Thenis called -integral of Π for Definition 41 ([
85])
. Let function be continuous. Thenis called -derivative of Π at Definition 42 ([
85])
. Let function be continuous. Thenis called -integral of Π for We give now some Ostrowski-type inequalities for q-differentiable convex functions.
Theorem 164 ([
86])
. Let be a q-differentiable function on with continuous and integrable on I where If is a convex function and then, for all Theorem 165 ([
86])
. Let be a q-differentiable function on with continuous and integrable on I where If is a convex function and then for we have for all For q-differentiable bounded functions, we present some Ostrowski-type inequalities.
Theorem 166 ([
87])
. Let be a continuous and q-differentiable function on If , then, for all for whereand Theorem 167 ([
87])
. Let be a continuous and q-differentiable function on If for , then, for all whereand In the next, we give Ostrowski-type inequalities for s-convex functions in the second sense.
Theorem 168 ([
88])
. Let be a q-differentiable function on with integrable on If is s-convex in the second sense on for unique and for all then, for all Theorem 169 ([
88])
. Let Π be as in Theorem 168. If is s-convex in the second sense on for unique and for all then, for all Theorem 170 ([
88])
. Let Π be as in Theorem 168. If is s-convex in the second sense on for unique and for all then, for all We present Ostrowski-type inequalities for twice quantum differentiable functions involving the quantum integrals.
Theorem 171 ([
89])
. Let be a twice q-differentiable function on such that and are continuous and integrable on Then, we have for all Theorem 172 ([
89])
. Let be a twice q-differentiable function on such that and are convex on Then, we have for all Theorem 173 ([
89])
. Let be a twice q-differentiable function on such that and for some and are convex on Then, we have for all Definition 43 ([
90])
. Let The Riemann–Liouville q-integrals of order are defined by In this section, q-fractional integral operators are used to construct a quantum analogue of Ostrowski-type fractional integral inequalities for the class of s-convex functions.
Theorem 174 ([
91])
. Let be a q-differentiable mapping in such a way If is s-convex in the second sense on for and for all then for and for all Theorem 175 ([
91])
. Let Π be as in Theorem 174. If is s-convex in the second sense on for and for all then we have for and for all Theorem 176 ([
91])
. Let Π be as in Theorem 174. If is s-convex in the second sense on for and for all then, we have for and for all In the following theorems, we present some post-quantum estimates of the Ostrowski-type inequality for n-polynomial convex functions.
Definition 44 ([
92])
. Let A nonnegative function is said to be an n-polynomial convex function if for every and we have Definition 45 ([
93])
. If function is continuous, then the left -derivative of Π at x is stated byIf exists for all , then the function Π is called -differentiable on .The left -integral is defined by Definition 46 ([
94])
. If function is continuous, then the right -derivative of Π at x is stated byIf exists for all , then the function Π is called -differentiable on .The right -integral is defined by Theorem 177 ([
94])
. Let be continuous and - differentiable function on with and be -integrable. If are n-polynomial convex functions and for all thenfor all Theorem 178 ([
94])
. Let Π be as in Theorem 177. If are n-polynomial convex functions, and for all then:for all Theorem 179 ([
94])
. Let Π be as in Theorem 177. If are n-polynomial convex functions, and for all then:for all Now, we give some estimates of post quantum Ostrowski-type inequalities for twice -differentiable functions involving - and -integrals. Let and .
Theorem 180 ([
95])
. If is a twice -differentiable function such that and are continuous and integrable functions on and , respectively. Then Theorem 181 ([
95])
. Let Π be as in Theorem 180. If and are convex functions for , then Theorem 182 ([
95])
. Let Π be as in Theorem 180. If and are convex functions for and , then 13. Ostrowski-Type Tensorial Inequalities in Hilbert Space
In this section we present Ostrowski-type inequalities for twice differentiable functions in the Hilbert space of tensorial type. Some preliminary concepts are necessary [
96]. Let
be intervals from
and let
be an essentially bounded real function defined on the product of the intervals. Let
be a
k-tuple of bounded selfadjoint operators on Hilbert spaces
such that the spectrum of
is contained in
for
We say that such a
k-tuple is in the domain of
If
is the spectral resolution of
for
we define
as bounded selfadjoint operator on the tensorial product
Now, we present Ostrowski-type inequalities for twice differentiable functions in the Hilbert space of tensorial type for fractional differential equations of order for convex and quasi-convex functions.
Theorem 183 ([
96])
. Suppose that f is continuously differentiable on I and is convex and are self-adjoint operators with then Theorem 184 ([
96])
. Suppose that f is continuously differentiable on I and is quasi-convex and are self-adjoint operators with then 14. Conclusions
In this survey, we have presented a variety of results on Ostrowski-type inequalities involving fractional integral operators and convex functions. This comprehensive review will inspire the researchers to acquire useful information about Ostrowski-type integral inequalities before pursuing their new research on the topic to develop it further. Moreover, it is expected that the present work will provide a guideline for developing numerous new results for Ostrowski-type inequalities involving the new fractional integral operators combined with different types of convex functions.