1. Introduction
One of the most well-known concepts in the field of function theory is the Hermite-Hadamard inequality, which was found by C. Hermite and J. Hadamard (and described in sources such as [
1], [
2] p.137). This inequality has several real-world applications in addition to its geometric interpretation.
The Hermite-Hadamard inequalities have been established by numerous mathematicians. It's important to note that the Hermite-Hadamard inequality, which naturally follows from Jensen's inequality, can be seen as a development of the idea of convexity. Recently, there has been renewed interest in the Hermite-Hadamard inequality for convex functions, leading to a wide range of improvements and expansions that have been thoroughly investigated (see, for example, publications like [
3,
4,
5,
6,
7,
8]).
Interval analysis is a crucial topic since it is used in math and computer models as one method of addressing interval uncertainty. Even though this theory has a long history going back to Archimedes' calculation of a circle's circumference, significant research on the subject was not published until the 1950s. The first book [
9] on interval analysis was published in 1966 by Ramon E. Moore, who is credited with developing interval calculus. After that, other academics studied the theory and uses of interval analysis.
Furthermore, by taking into account interval-valued functions in [
10,
11,
12,
13], well-known inequality types as Ostrowski, Minkowski, and Beckenbach, as well as some of their applications, were supplied. Additionally, Budak et al. in [
14] developed a few inequalities utilizing interval-valued Riemann-Liouville fractional integrals. The definition of interval-valued harmonically convex functions was provided by Liu et al. in [
15], and as a result, they are able to derive several Hermite-Hadamard type inequalities, including interval fractional integrals. The authors provided a fuzzy integral-based variation of Jensen's inequality for interval-valued functions in [
16] and [
17] and demonstrated several integral inequalities, [
18,
19,
20,
21,
22,
23,
24,
25,
26,
27,
28,
29]. In their proofs of Hermite-Hadamard type inequalities for set-valued functions in [
30] and [
31,
32], Mitroi et al. made use of general forms of interval-valued convex functions. Rom'an Flores et al. found a few Gronwal type inequalities for interval-valued functions in [
33]. Zhao et al. showed many kinds of integral inequalities for interval-valued functions in [
34,
35].
In [
36], Jleli and Samet discovered brand-new Hermite-Hadamard type inequality involving fractional integrals with regard to a different function. Fractional integrals of a function with respect to another function were first introduced by Tunc in [
37]. The Riemann-Liouville and Hadamard fractional integrals were generalized into a single form by Katugompala's novel fractional integration. Budak and Agarwal used generalized fractional integrals, which generalize some significant fractional integrals like the Riemann-Liouville fractional integrals, the Hadamard fractional integrals, and the Katugampola fractional integrals in [
38], to establish the Hermite-Hadamard-type inequalities for co-ordinated convex function. Interval-valued left- and right-sided generalized fractional double integrals were defined by Kara et al. [
39]. Numerous authors have concentrated on interval-valued functions in recent years. The authors of [
40] introduced the idea of interval-valued general convex functions and used it to demonstrate a number of novel Hermite-Hadamard type inequalities. A fractional version of Hermite-Hadamard type inequalities for interval-valued harmonically convex functions was also provided by the authors in [
41]. Researchers recently expanded the idea of interval-valued convexity and described various types of
-convexity for interval-valued functions in [
42,
43,
44,
45,
46]. For
-fuzzy-number-valued convex functions, they also discovered a large number of Hermite-Hadmard type inequalities.
To express the collection of all positive fuzzy numbers over the real numbers, we introduce the notation in the context of this article. The terms , and refer to the set of all that are Riemann integrable real valued functions, Aumann’s integrable IV-Fs and fuzzy Aumann’s integrable on the interval . The following theorem draws a link between functions that are integrable in the sense of Riemann (-integrable) and functions that are integrable in the sense of . Additionally, the sign "" is used to denote the up and down () fuzzy inclusion relationship for and belonging to , where is thought of as a fuzzy subset of . If and only if for -levels, the conditions is met, this -inclusion is true. Integral fuzzy inequalities generated from s have recently attracted the attention of several academics:
Theorem 1 [
35]: Assume that the
-convex
is
with
for all
and for all
. Then there are the disparities:
We provide the ideas of generalized fractional integrals for two-variable in order to demonstrate Hermite-Hadmard type inequalities for convex and coordinated convex functions, which are inspired by ongoing investigations. The main benefit of the newly established inequalities is that they can be converted into classical Hermite-Hadamard integral inequalities for coordinated -convex s as well as fuzzy Riemann-Liouville fractional Hermite-Hadamard, Hadamard, and Katugampola fractional Hermite-Hadamard inequalities without having to prove each one separately.
The format of this essay is as follows: A brief summary of the foundations of fuzzy-number-valued calculus and other relevant works in this area are presented in
Section 2. In
Section 3, we provide some generalized fractional integrals for
-convex
with two variables. For
-convex
, we create a novel Hermite-Hadamard type inequality. Several Hermite-Hadamard type inequalities for coordinated
-convex
are parented in
Section 3. It is also taken into consideration how these findings compare to findings of a similar nature in the literature. Finally, Section 4 makes some suggestions for additional study.
2. Preliminaries
We will go through the fundamental terminologies and findings in this section, which aid in comprehending the ideas behind our fresh findings.
Definition 1
([47,48]). Given , the level sets or cut sets are given by and by
These sets are known as -level sets or -cut sets of .
Proposition 1 ([49]). Let . Then, relation is given on by when and only when , for every which are left- and right-order relations.
Proposition 2 ([46]). Let . Then, relation is given on by when and only when for every which is order relation on .
Remember the approaching notions, which are offered in the literature. If
and
, then, for every
the arithmetic operations addition “
, multiplication “
, and scaler multiplication “
are defined by
Equations (4) through (6) have immediate consequences for these outcomes.
Theorem 2 ([47]). The space dealing with a supremum metric, i.e., for
is a complete metric space, where indicates the well-known Hausdorff metric on the space of intervals.
Theorem 3. Let be a , its s are classified according to their -levels are given by and Then, is -integrable over if and only if, and are both -integrable over . Moreover, if is -integrable over then
denotes the collection of all -integrable s over .
Fuzzy Aumann’s and fractional calculus on coordinates
Definition 2. [16,48] Let be and . Then interval Riemann-Liouville-type integrals of are defined as
where and is the gamma function.
Recently, Allahviranloo et al. [49] introduced the fuzzy version of defined the fractional integral integrals such that:
Definition 3. Let and be the collection of all Lebesgue measurable s on. Then, the fuzzy left and right Riemann-Liouville fractional integral of with order are defined by
respectively, where
is the Euler gamma function. The fuzzy left and right Riemann-Liouville fractional integral
based on left and right end point functions can be defined, that is
The right Riemann-Liouville fractional integral, denoted by, can also be defined using the left and right end point functions.
Theorem 4. [27] Let be a -convex on whose -cuts set up the sequence of s are given by for all and for all . If , then
Theorem 5. [27] Let be two -convex s. Then, from -cuts, we set up the sequence of s are given by and for all and for all . If is fuzzy Riemann integrable, then
where , and
Interval and fuzzy Aumann's type integrals are defined as follows for coordinated and coordinated :
Theorem 6. [34] Let be a on coordinates, whose -cuts set up the sequence of s are given by for all and for all Then is fuzzy double integrable (-integrable) over if and only if and both are -integrable over Moreover, if is -integrable over then
for all
The family of all -integrable of s over coordinates and -integrable functions over coordinates are denoted by and for all
Here is the main definition of fuzzy Riemann-Liouville fractional integral on the coordinates of the function by:
Definition 4. [29] Let and . The double fuzzy interval Riemann-Liouville-type integrals of order are defined by:
Here is the newly defined concept of coordinated convexity over fuzzy number space in the codomain via -relation given by:
Definition 5. [34] The is referred to be coordinated -convex on if
for alland where If inequality (23) is reversed, then is referred to be coordinate concave on .
Lemma 1. [34] Let be a coordinated on . Then, is coordinated -convex on if and only if there exist two coordinated -convex s , and , .
Theorem 7. [34] Let be a on . Then, from -levels, we get the collection of s are given by
for all and for all . Then, is coordinated -convex on if and only if, for all and are coordinated convex and concave functions, respectively.
Example 1. We consider the defined by,
Then, for each we have . Since endpoint functions are coordinate concave functions for each . Hence, is coordinate -convex .
From Lemma 1 and Example 1, we can easily note that each -convex is coordinated -convex . But the converse is not true.
Remark 1. If one assumes that
with
, then
is referred to be as a coordinated convex function if
meets the stated inequality here, see [
41]:
Let one assumes that
with
and
is affine function and
is a concave function. If the stated inequality here, see [32:]
is true.
Definition 6. Let be a on . Then, from -levels, we get the collection of IVMs are given by
for all and for all . Then, is coordinated left--convex (concave) on if and only if, for all and are coordinated convex (concave) and affine functions on , respectively.
Definition 7. Let be a on . Then, from -levels, we get the collection of IVMs are given by
for all and for all . Then, is coordinated right--convex (concave) on if and only if, for all and are coordinated affine and convex (concave) functions on , respectively.
Theorem 8. Let be a coordinated convex set, and let be a . Then, from -levels, we obtain the collection of IVMs are given by
for all and for all . Then, is coordinated -concave on if and only if, for all and are coordinated concave and convex functions, respectively.
Proof. The demonstration of proof of Theorem 8 is similar to the demonstration proof of Theorem 7.
Example 2. We consider the s defined by,
Then, for each we have . Since endpoint functions are coordinate concave and convex functions for each . Hence is coordinated -concave .
In the next results, to avoid confusion, we will not include the symbols , , , , and before the integral sign.
The main goal of this article is to develop a number of original fractional coordinated integral inequalities for the Hermite-Hadamard types using an coordinated -concave . We acquired the most recent estimates for mappings whose products are coordinated -concave s using the fuzzy fractional operators.
3. Main Results
Here is first result of coordinated integral inequalities for the Hermite-Hadamard type using the fuzzy fractional operators via coordinated -concave s.
Theorem 9. Let be a coordinate -convex on . Then, from -cuts, we set up the sequence of are given by for all and for all . If , then following inequalities holds:
If
coordinated concave
then,
Proof. Let be a coordinated -convex . Then, by hypothesis, we have
By using Theorem 7, for every
, we have
By using Lemma 1, we have
From (30) and (31), we have
Since
and
, both are coordinated
-convex-
s, then from inequality (15), for every
, inequalities (32) and (43) we have
Since
, then (34) can be written as
Multiplying double inequality (36) by
and integrating with respect to
over
we have
Again, multiplying double inequality (36) by
and integrating with respect to
over
we have
Since from
-cuts, we obtain the collection of
s
, then we have
Similarly, since
then, from the (35), (41) and (42), we have
The second, third, and fourth inequalities of (28) will be the consequence of adding the inequalities (41), (42), (43) and (44).
Now, for any
, we have inequality (15)'s left portion.
The following inequality is created by adding the two inequalities (45 and 46):
Similarly, since we obtain the set of
s
for for
, the inequality can be expressed as follows:
The first inequality of (28) is this one.
Now, for any
, we have inequality (15)'s right portion:
Summing inequalities (48), (49), (50) and (51), and then taking multiplication of the resultant with
, we have
Since we receive the collection of
s
from
-cuts, we have
This is the final inequality of (28) and the conclusion has been established.
Example 3. We assume the s defined by,
then, for each
we have
. Since end point functions
are coordinate concave functions for each
. Hence
is coordinate concave
.
Hence, Theorem 9 has been verified.
Remark 2. If one assumes that
and
, then from (28), as a result, there will be inequity, see [
27]:
If one assumes that
and
and
is coordinated left-
-convex, then from (28), as a result, there will be inequity, see [
22]:
If
with
, then from (28), we succeed in bringing about the upcoming inequity, see [
21]:
If
with
, the by (28), we succeed in bringing about the upcoming inequity, see [
20]:
If
is coordinated right-
-convex and
with
, then from (28), we succeed in bringing about the upcoming inequity, see [
23]:
Theorem 10. Let be a coordinate -convex s on . Then, from -cuts, we set up the sequence of s are given by and for all and for all . If , then following inequalities holds:
If
and
are both coordinated concave
s on
, then inequality above can be expressed as follows:
and for each
,
,
and
are defined as follows:
Proof. Let and be two coordinated -convex s on . Then
Since
and
both are coordinated
-convex
s, Lemma 1 states that
Since
, and
are
s, then by inequality (16), we have
Now for all for all
, we have
Multiplying double inequality (61) by
and integrating with respect to
over
we get
Again, multiplying double inequality (61) by
and integrating with respect to
over
we gain
Summing (62) and (63), we have
Now, once more with the aid of integral inequality (16), we obtain the following relationship for the first two integrals on the right-hand side of (64):
From (65)-(68), inequality (64) we have
Since we get the collection of s from -cuts, the aforementioned inequality can be expressed as an inequality (59). The conclusion has therefore been established.
Remark 3. If one assumes that
and
, then from (59), as a result, there will be inequity, see [
28]:
If
is coordinated left-
-convex and one assumes that
and
, then from (59), as a result, there will be inequity, see [
22]:
If
with
then, by (59), we succeed in bringing about the upcoming inequity, see [
21]:
If
with
, then by (59), we succeed in bringing about the upcoming inequity, see [
20]:
If
and
with
, then from (59), we succeed in bringing about the upcoming inequity, see [
27]:
Theorem 11. Let be a coordinated -convex s on . Then, from -cuts, we set up the sequence of s are given by and for all and for all . If , then following inequalities holds:
If
and
both are coordinate concave
s on
, then the inequality above can be expressed as follows
where , , and are given in Theorem 10.
Proof. Since be two -convex s, then from inequality (17) and for each we have
Adding (76) and (77), and then taking the multiplication of the resultant one by 2, we obtain:
By adding (76) and (77), multiplying the result by 2, we arrive at:
By Lemma 1, for each integral on the right-hand side of (78) and integral inequality (17) once more lead us to arrive at:
From inequalities (79) to (90), inequality (78) we have
By Lemma 1, for each integral on the right-hand side of (91) and integral inequality (16) once more lead us to arrive at:
From (88) to (95), (91) we have
The conclusion has therefore been established.
Remark 4. If one assumes that
and
, then from (74), as a result, there will be inequity, see [
28]:
If
is coordinated left-
-convex and one assumes that
and
, then from (74), as a result, there will be inequity, see [
22]:
If
with
, then from (74), we succeed in bringing about the upcoming inequity, see [
20]:
If
with
, then from (74), we succeed in bringing about the upcoming inequity, see [
21]:
If
and
with
, then from (74), we succeed in bringing about the upcoming inequity, see [
27]: