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Escuela de Ciencias Físicas y Matemáticas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre 1076. Apartado, Quito 17-01-2184, Ecuador
Department of Mathematics, Faculty of Technical Science, University Ismail Qemali, L. Pavaresia, Vlora 1001, Albania
Departamento de Técnicas Cuantitativas, Decanato de Ciencias Económicas y Empresariales, Universidad Centroccidental Lisandro Alvarado, Av. 20. esq. Av. Moran, Edf. Los Militares, Piso 2, Ofc.2, Barquisimeto 3001, Venezuela
Author to whom correspondence should be addressed.
In this work, a study is conducted on the Hermite–Hadamard inequality using a class of generalized convex functions that involves a generalized and parametrized class of special functions within the framework of quantum calculation. Similar results can be obtained from the results found for functions such as the hypergeometric function and the classical Mittag–Leffler function. The method used to obtain the results is classic in the study of quantum integral inequalities.
In the eighteenth century (1707–1783), Euler started some studies about what we know now as quantum calculus (1707–1783). As T. Ernst says in , it was John von Neumann who first proposed that group representation theory can be used in quantum mechanics. In , F. J. Jackson started a systematic study of q-calculus and introduced the q-definite integrals. Some branches of mathematics and physics, such as number theory, orthogonal polynomials, combinatory, basic hypergeometric functions, mechanics, and quantum and relativity theory, have been enriched by the research work of various authors as T. Ernst [3,4], H. Gauchman , V. Kac and P. Cheung , and M.E.H. Ismail [7,8]. Also, certain famous integral inequalities have been studied in the frame of q-calculus [9,10].
Convex functions have played an important role in the development of inequalities, as it is evidenced in functional analysis, harmonic analysis, specifically in interpolation theory, control theory and optimization, and it is shown in the following works C.P. Niculescu , C. Bennett and R. Sharpley , N.A. Nguyen et al. , Ş. Mititelu and S. Trenţă , S. Trenţă [15,16,17]. This property was defined by J.L.W.V. Jensen in the following works [18,19] as follows.
The concept of convexity has been extended and generalized in several directions. Various types of generalized convexity have appeared in different research works, some of them modify the domain or range of the function, always maintaining the basic structure of a convex function. Among them are: s-convexity in the first and second sense , P-convexity , MT-convexity , and others [24,25,26,27,28,29,30,31]. The well-known inequality of Hermite–Hadamard is famous throughout mathematical literature, being of interest in the relationship between arithmetic means, as an argument and as an image of the ends of the interval where a convex function is defined. It was established as follows.
Let be a convex function on I and with Then the following inequality holds:
This inequality (1) is also known as trapezium inequality.
The trapezium type inequality has remained a subject of great interest due to its wide applications in the field of mathematical analysis. For other recent results which generalize, improve and extend the inequality (1) through various classes of convex functions interested readers are referred to [32,33,34,35,36,37,38,39].
Let K be a non empty closed set in and a continuous function.
Noor, in , introduced a new class of non-convex functions, the so-called -convex as follows:
The function on the ϕ-convex set K is said to be ϕ-convex, if
The function f is said to be -concave iff is -convex. Note that every convex function is -convex but the converse does not hold in general.
Raina, in , introduced a class of functions defined by
is a bounded sequence of positive real numbers. Note that, if we take in (2) and
where , and are parameters which can take arbitrary real or complex values (provided that and the symbol denotes the quantity
and restrict its domain to (with ), then we have the classical hypergeometric function, that is
Also, if with and restricting its domain to in (2) then we have the classical Mittag–Leffler function
Finally, let recall the new class of set and new class of function involving Raina’s function introduced by Vivas-Cortez et al. in , the so-called generalized -convex set and also the generalized -convex function.
Let and are bounded sequence of positive real numbers. A non empty set K is said to be generalized ϕ-convex set, if
where is Raina’s function.
Let and are bounded sequence of positive real numbers. If a function satisfies the following inequality
for all and then f is called generalized ϕ-convex.
For and in Definition 4, then we have so we recapture Definition 1. Also, under suitable choice of we get Definition 2.
Recently, several authors have utilized quantum calculus as a strong tool in establishing new extensions of trapezium-type and other inequalities, see [6,41,42,43,44,45,46,47] and the references therein.
We recall now some concepts from quantum calculus. Let be an interval and be a constant.
(). Let be a continuous function and Then q-derivative of f on I at x is defined as
We say that f is q-differentiable on I provided exists for all Note that if in (5), then where is the well-known q-derivative of the function defined by
(). Let be a continuous function. Then the q-integral on I is defined by
for Note that if then we have the classical q-integral, which is defined by
(). Assume that are continuous functions, Then, for we have
(). (q-Hermite–Hadamard) Let be a convex continuous function on I and Then the following inequality holds:
Sudsutad et al. in , established the following three q-integral identities to be used in this paper.
Let be a constant. Then the following equality holds:
Let be a constant. Then the following equality holds:
Let be a q-differentiable function on with be continuous and integrable on where Then the following identity holds:
Motivated by the above literatures, the paper is structured as follows: In Section 2, an identity for a q-differentiable functions involving Raina’s generalized special function will be established. Applying this result, we develop some new quantum estimates inequalities for the generalized -convex functions. Some known results will be recaptured as special cases. Also, new quantum Hermite–Hadamard type inequality for the product of two generalized -convex functions will be derived. In Section 3, a briefly conclusion is given as well.
2. Some Quantum Trapezium-Type Inequalities
Throughout this paper the following notations are used:
where and are bounded sequence of positive real numbers. Let denote the interior of Also, for convenience we write for where
Let be a q-differentiable function on with be continuous and integrable on Then the following identity holds:
Using Definitions 5 and 6, we have
Multiplying both sides of above equality by we get the desired result. The proof of Lemma 4 is completed. □
Taking in Lemma 4, we obtain the following new identity:
Taking in Lemma 4, we get Lemma 3.
Let be a q-differentiable function on with be continuous and integrable on If is generalized ϕ-convex on then the following inequality holds:
Using Lemmas 1, 2 and 4, the fact that is generalized -convex function, we have
Since Raina’s generalized special function is parametrized, then for different appropriate parameter values of and it is possible to obtain new inequalities using the theorems and their corollaries presented in this work. It is useful to note that the results can be applied to derive some inequalities using special means and others special functions.
In the present text we have found an identity (Lemma 4) that relates the right inequality of Hermite Hadamard, from which important and new estimates have been established for them in the quantum calculus scenario, using a new class of generalized convex functions called generalized -convex functions, see Theorems 4–9. In the proofs the Raina generalized function, the Hölder inequality, and the power mean inequality were used, and as an end result, an esteem for the integral of the product of functions that have the property of being -convex. Some corollary and commentary regarding the main results have also been presented, and as a final note we draw attention to some results involving the function of Mittag–Leffler and hypergeometric function as cases of the results obtained.
Since quantum calculus has large applications in many areas of mathematics, the class of generalized -convex can be applied to obtain new results in convex analysis, special functions, quantum mechanics, related optimization theory, mathematical inequalities, and also stimulate further research in areas of pure and applied sciences.
All authors contributed equally in the preparation of the present work taking into account the theorems and corollaries presented, the review of the articles and books cited, formal analysis, investigation, writing—original draft preparation and writing—review and editing. All authors have read and agreed to the published version of the manuscript.
This research was funded by Dirección de Investigación from Pontificia Universidad Católica del Ecuador in the research project entitled: Some inequalities using generalized convexity.
Miguel J. Vivas-Cortez thanks to Dirección de Investigación from Pontificia Universidad Católica del Ecuador for the technical support given to the research project entitled: Algunas desigualdades de funciones convexas generalizadas (Some inequalities of generalized convex functions). Jorge E. Hernández Hernández wants to thank to the Consejo de Desarrollo Científico, Humanístico y Tecnológico (CDCHT) from Universidad Centroccidental Lisandro Alvarado (Venezuela), also for the technical support given in the development of this article.
Conflicts of Interest
The authors declare no conflict of interest.
Ernst, T. The History of Q-Calculus and a New Method; Department of Mathematics, Uppsala University: Stockholm, Sweden, 2000. [Google Scholar]
Jackson, F.H. On a q-definite integrals. Q. J. Pure Appl. Math.1910, 41, 193–203. [Google Scholar]
Ernst, T. The different tongues of q-calculus. Proc. Eston. Acad. Sci.2008, 57, 81–99. [Google Scholar] [CrossRef]
Ernst, T. A Comprehensive Treatment of q-Calculus; Springer: Basel, Switzerland, 2012. [Google Scholar]
Niculescu, C.P. An invitation to convex function theory. In Order Structures in Functional Analysis; Editura Academiei Romane: Bucharest, Romania, 2001. [Google Scholar]
Bennett, C.; Sharpley, R. Interpolation of Operators; Academic Press: Boston, MA, USA, 1998. [Google Scholar]
Nguyen, N.A.; Gulan, M.; Olaru, S.; Averbe, P.R. Convex Lifting: Theory and Control Applications. IEEE Trans. Autom. Control2010, 63, 1–16. [Google Scholar] [CrossRef]
Mititelu, Ş.; Trenţă, S. Efficiency conditions in vector control problems governed by multiple integrals. J. Appl. Math. Comp.2018, 57, 647–665. [Google Scholar] [CrossRef]
Trenţă, S. Multiobjective Fractional Variational Problem on Higher-Order Jet Bundles. Comm. Math. Stat.2016, 4, 323–340. [Google Scholar] [CrossRef]
Trenţă, S. On a New Class of Vector Variational Control Problems. Num. Funct. Anal. Optim.2018, 39, 1594–1603. [Google Scholar] [CrossRef]
Trenţă, S. KT-geodesic pseudoinvex control problems governed by multiple integrals. J. Nonlinear Convex Anal.2019, 20, 73–84. [Google Scholar]
Jensen, J.L.W.V. Om konvexe Funktioner og Uligheder mellen Middelvaerdier. Nyt. Tidsskr. Math.1905, 16, 49–68. [Google Scholar]
Jensen, J.L.W.V. Sur les fonctions convexes et les inegalités entre les valeurs moyennes. Acta Math.1906, 30, 175–193. [Google Scholar] [CrossRef]
Tomar, M.; Agarwal, P.; Jleli, M.; Samet, B. Certain Ostrowski type inequalities for generalized s-convex functions. J. Nonlinear Sci. Appl.2017, 10, 5947–5957. [Google Scholar] [CrossRef][Green Version]
Alomari, M.; Darus, M.; Dragomir, S.S.; Cerone, P. Ostrowski type inequalities for functions whose derivatives are s-convex in the second sense. Appl. Math. Lett.2010, 23, 1071–1076. [Google Scholar] [CrossRef]
Akdemir, A.O.; Özdemir, M.E. Some Hadamard-type inequalities for coordinated P-convex functions and Godunova-Levin functions. AIP Conf. Proc.2010, 1309, 7–15. [Google Scholar]
Liu, W.; Wen, W.; Park, J. Hermite–Hadamard type inequalities for MT-convex functions via classical integrals and fractional integrals. J. Nonlinear Sci. Appl.2016, 9, 766–777. [Google Scholar] [CrossRef]
Bracamonte, M.; Giménez, J.; Vivas-Cortez, M.J. Hermite–Hadamard-Fejér Type Inequalities for Strongly (s,m)-Convex Functions with Modulus c, in Second Sense. Appl. Math. Inf. Sci.2016, 10, 2045–2053. [Google Scholar] [CrossRef]
Hernández Hernández, J.E. On Some New Integral Inequalities Related with the Hermite–Hadamard Inequality via h-Convex Functions. MAYFEB J. Math.2017, 4, 1–12. [Google Scholar]
Hernández Hernández, J.E. On log-(m,h1,h2)-convex functions and related integral inequalities. Int. J. Open Prob. Compt. Math.2019, 12, 43–59. [Google Scholar]
Vivas-Cortez, M.J.; García, C.; Hernández Hernández, J.E. Ostrowski Type Inequalities for Functions Whose Derivative Modulus is Relatively Convex. Appl. Math. Inf. Sci.2019, 13, 121–127. [Google Scholar] [CrossRef]
Vivas-Cortez, M.J.; Hernández Hernández, J.E. Ostrowski and Jensen type inequalities via (s,m)-convex functions in the second sense. Boletin de la Sociedad Matemática Mexicana2019, in press. [Google Scholar] [CrossRef]
Vivas-Cortez, M.J.; Medina Viloria, J. Hermite–Hadamard Type Inequalities for Harmonically Convex Functions on n-Coordinates. Appl. Math. Inf. Sci. Lett.2018, 6, 1–6. [Google Scholar]
Vivas-Cortez, M.J.; García, C. Ostrowski Type Inequalities for Functions Whose Derivatives are (m,h1,h2)-Convex. Appl. Math. Inf. Sci.2017, 11, 79–86. [Google Scholar] [CrossRef]
Delavar, M.R.; De La Sen, M. Some generalizations of Hermite–Hadamard type inequalities. SpringerPlus2016, 5, 1–9. [Google Scholar]
Hernández Hernández, J.E. Some fractional integral inequalities of Hermite Hadamard and Minkowski type. Selecciones Matemáticas (Universidad de Trujillo)2019, 6, 41–48. [Google Scholar] [CrossRef][Green Version]
Kashuri, A.; Liko, R. Some new Hermite–Hadamard type inequalities and their applications. Stud. Sci. Math. Hung.2019, 56, 103–142. [Google Scholar] [CrossRef]
Noor, M.A. Some new classes of non-convex functions. Nonlinear Funct. Anal. Appl.2006, 11, 165–171. [Google Scholar]
Set, E.; Noor, M.A.; Awan, M.U.; Gözpinar, A. Generalized Hermite–Hadamard type inequalities involving fractional integral operators. J. Inequal. Appl.2017, 169, 1–10. [Google Scholar] [CrossRef][Green Version]
Vivas-Cortez, M.J.; Hernández Hernández, J.E. Hermite–Hadamard Inequalities type for Raina’s fractional integral operator using η-convex functions. Revista de Matemática Teoría y Aplicaciones2019, 26, 1–19. [Google Scholar]
Vivas-Cortez, M.J.; Liko, R.; Kashuri, A.; Hernández Hernández, J.E. New Quantum Estimates of Trapezium-Type Inequalities for Generalized ϕ-Convex Functions. Mathematics2019, 7, 1047. [Google Scholar] [CrossRef][Green Version]
Cortez, M.V. Relative strongly h-convex functions and integral inequalities. Appl. Math. Inf. Sci. Lett.2016, 4, 39–45. [Google Scholar] [CrossRef]
Raina, R.K. On generalized Wright’s hypergeometric functions and fractional calculus operators. East Asian Math. J.2005, 21, 191–203. [Google Scholar]
Alp, N.; Sarikaya, M.Z.; Kunt, M.; Iscan, I. q-Hermite–Hadamard inequalities and quantum estimates for midpoint type inequalities via convex and quasi-convex functions. J. King Saud Univ. Sci.2018, 30, 193–203. [Google Scholar] [CrossRef][Green Version]
Liu, W.J.; Zhuang, H.F. Some quantum estimates of Hermite–Hadamard inequalities for convex functions. J. Appl. Anal. Comput.2017, 7, 501–522. [Google Scholar]
Noor, M.A.; Noor, K.I.; Awan, M.U. Some quantum estimates for Hermite–Hadamard inequalities. Appl. Math. Comput.2015, 251, 675–679. [Google Scholar] [CrossRef]
Noor, M.A.; Noor, K.I.; Awan, M.U. Quantum analogues of Hermite–Hadamard type inequalities for generalized convexity. In Computation, Cryptography and Network Security; Daras, N., Rassias, M.T., Eds.; Springer: Cham, Switzerland, 2015; pp. 413–439. [Google Scholar]
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