1. Introduction
Fractional calculus composed on fractional derivatives, fractional anti-derivatives and special functions. The Mittag-Leffler (ML) function, gamma function, beta function and other such functions are used in defining mathematical models for real world problems. The exponential function is unique in the sense of its existence and properties, and it has very important place in the theory of differential equations. The ML function is a generalization of exponential function and is equally important in solving fractional differential equations. Gösta Mittag-Leffler introduced this function in [
1]. There are plenty of mathematical concepts, equations, and models in different subjects of science which were extended and generalized with the help of this ML function. The ML function is given in the following equation:
where
and
, and
is the gamma function.
The ML function defined in (
1) involves one parameter, and there also exist many extended and generalized ML functions in literature. For more information and detail about ML function one can see [
2,
3,
4], and references therein. ML functions are frequently utilized in defining operators of fractional derivatives and fractional integration.
It is also presented in generalized form by using generalized beta and gamma functions along with pochhammer symbol. Currently, so called unified ML function is introduced in [
5], and given in the following definition. Here we assume all the convergence conditions are satisfied and exclude the detail, one can see [
5].
Definition 1.
The unified ML function is defined by;
where , ,
and is the extension of well known beta function.
The unified fractional integral operators containing the above ML function are defined as follows:
Definition 2.(see[5]) Let . Then , the fractional integral operator containing the unified ML function along with all the convergence conditions is defined by;
By setting
,
and
in above definitions, one can get the generalized Q function
is the generalized Q function defined in [
6] and the fractional integral operators
as given in [
7]. Next, we give the following definition of integral operators.
Definition 3..
[8] Let , be a positive function and let be a differentiable and strictly increasing function. Also let be an increasing function on and . Then the unified integral operator is given by;
By setting
,
and
in (
8) and (
9), one can get the integral operator associated with generalized Q function given in [
7]:
where
. If
and
are increasing functions, one can note that for
, the kernel
satisfies the forthcoming inequality:
Moreover, the forthcoming inequalities hold which will be utilized to prove the results of this paper:
Convex functions have wide range of applications in various subjects of different fields including physics, mathematics, statistics, optimization, graph theory and economics. In mathematical analysis, integral and discrete versions of classical inequalities are studied very frequently. A celebrated Jensen’s inequality is an analytic approach to define a convex function. Many classical inequalities are straightforward consequences of the Jensen inequality. Because of analytical representation of a convex function, the notion of convexity is extended and generalized in many terms. For instance
m-,
s-,
h-, and many other convexities were defined by preserving an analytic inequality satisfied by a convex function, see [
9,
10,
11,
12].
New defined convexities along with fractional integrals have been utilized to obtain generalized and refined versions of classical inequalities by Hadamard, Ostrowski, Minkowski, Chebyshev, Grüss etc. One of the most extensively studied inequality is the Hadamard inequality. Many researchers have studied it for new classes of convex functions. For a detailed study on Hadamard inequalities for different types of convex functions, one can see [
13,
14,
15,
16,
17,
18,
19]. Our aim in this paper is to establish some integral inequalities for refined
-convex functions.
The definition of refined -convex function is given as follows.
Definition 4..
[20] Assume that , are intervals with , and is a non-negative function. A function is called refined -convex function if the forthcoming inequality holds
where , , .
From the above definition, one can obtain the definitions of refined
-, refined
-, refined
-, refined
-convexities along with many classes of refined convexities. Let we denote class of refined
-
p-convex functions defined over
I by
. A function
satisfies the forthcoming inequalities which will be applied to establish the main results of this paper in the forthcoming section:
In upcoming
Section 2, we prove Theorem 1 by applying the inequalities (
19), (
20), (
14) and (
15). In the same section Theorem 3 is established by using inequalities (
21), (
16), (
17) and the Lemma 1, Theorem 2 is established by using inequalities (
14) and (
15). Consequences of each result are explained at the end of proofs. In
Section 3, we give some Hadamard type inequalities. Throughout the paper we assume that all the notions described in
Section 1 are valid.