Exploring the (h, m)-Convexity for Operators in Hilbert Space

Ekadion Maulana, Corina Karim, Mila Kurniawaty

Abstract


This study examines the concept of operator (h, m)-convexity within the context of Hilbert spaces, aiming to advance the understanding of operator convex functions. Operator convex functions play a pivotal role in various mathematical disciplines, particularly in optimization and the study of inequalities. The paper introduces the notion of an operator (h, m)-convex function, which generalizes existing classes of operator convexity, and explores its fundamental properties. The methodological framework relies on a theoretical analysis of bounded operators and their relationships with other forms of operator convex functions. Key findings demonstrate that, under certain conditions, the product of two operator convex functions retains operator convexity. Furthermore, the study establishes convergence results for matrix (h, m)-convex functions. These contributions enhance the theoretical foundation of operator convexity, offering a basis for future research and applications. The results not only deepen the understanding of operator (h, m)-convex functions but also support the development of sharper inequalities, thereby broadening the applicability of operator convexity within mathematical analysis.

Keywords


operator convexity; (h, m)-convexity; (h, m)-convex functions; matrix convexity; Hilbert space operators.

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References


D. Henrion, "Convexity", The Princeton Companion to Applied Mathematics, part II, Princeton University Press, 2015.

J. E. Pečarić, F. Proschan, and Y. L. Tong, Convex Functions, Partial Orderings, and Statistical Application, Academic Press, San Diego, 1992.

G. H. Toader, "Some generalizations of the convexity," J Proc. Colloq. Approx. Optim. Cluj-Naploca, pp. 329-338, 1984.

T. Lara, R. Quintero, E. Rosales, and J. Sanchez, "On strongly Jensen m-convex functions," Journal of Pure Mathematical Sciences, vol. 6, pp. 87-94, 2017.

S. Varošanec, "On h-convexity," Journal of Mathematical Analysis and Applications, vol. 326, no. 1, pp. 303-311, Elsevier, 2007.

E. K. Godunova and V. I. Levin, "Inequalities for functions of a broad class that contains convex, monotone and some other forms of functions," Proceedings of (Russian) Numerical Mathematics and Mathematical Physics, vol. 166, pp. 138-142, 1985.

H. Hudzik and L. Maligranda, "Some remarks on s-convex functions," Aequationes mathematicae, vol. 48, pp. 100-111, 1994.

S. Sezer, "The Hermite–Hadamard inequality for s-convex functions in the third sense," AIMS Math, vol. 6, no. 7, pp. 7719-7732, 2021.

C. E. M. Pearce and A. M. Rubinov "P-functions, quasi-convex functions, and

Hadamard-type Inequalities, Journal of Mathematical Analysis and Applications, vol. 240, pp. 92-104, 1999.

M. E. Özdemir, "Some inequalities for the s-Godunova–Levin type functions," Journal of Mathematical Sciences, vol. 9, pp. 27-32, 2015.

M. E. Özdemir, A. O. Akdemir, E. Set, "On (h,m)-convexity and Hadamard type inequalities," Transylvanian Journal of Mathematical and Mechanics, vol. 8, no. 1, pp. 51-58, 2016.

B. Bayraktar and M. Gürbüz, "On some integral inequalities for (s, m)-convex functions," TWMS J. App. Eng. Math., vol. 10, no. 2, pp. 288-295, 2020.

M. Sertbaş and İ. Mihyaz, "Some results for (s, m)-convex function in the second sense," Maltepe Journal of Mathematics, vol. IV, no. 1, pp. 1-8, 2022.

M. A. Noor, K. I. Noor, and M. U. Awan, "Fractional ostrowski inequalities for (s, m)-Godunova-Levin functions," Ser. Math. Inform, vol. 30, no. 4, pp. 489-499, 2015.

R. Bhatia, Matrix Analysis, Springer-Verlag, New York, 1997.

N. Sharma, "Equality conditions for the quantum f -relative entropy and generalized data processing inequalities," Quantum Inf Process, vol. 11, pp. 137-160, 2012.

V. Kaleibary, M. R, Jabbarzadeh, and S. Furuichi, "Operator geodesically convex functions and their applications," Linear and Multilinear Algebra, vol. 71, no. 8, pp. 1280-1294, 2023.

Y. Erdaş, E. Unluyol, S. Salaş, "Some new inequalities of operator m-convex functions and applications for synchronous-asynchronous functions," Complex Analysis and Operator Theory, vol. 13, pp. 3871-3881, 2019.

E. Unluyol, Y. Erdaş, and S. Salaş, "Operator (α,m)-convex functions and applications for synchronous and asynchronous functions," Mathematical Sciences and Applications E-Notes, vol. 7, no. 2, pp. 225-236, 2019.

M. Fujii, J. Mićić, H. Mićić, and Y. Seo, Recent Developments of Mond-Pečarić Method in Operator Inequalities, vol. 4. Zagreb: Elemen, 2012.

S. Salaş, E. Unluyol, D. Yardimciel, "Operator (h,m)-convexity and Hermite-Hadamard type inequalities," Ordu University Journal of Science and Technology, vol. 7, no. 2, pp. 367-377, 2017.

L. Berbesi, T. Lara, P. Pena, and E. Rosales, "On operator m-convex functions in Hilbert space," UPI Journal of Mathematics and Biostatistics, vol. 1, no. 2, JMB11, 2018.

Y. Erdaş, E. Unluyol, and S. Salaş, "The Hermite-Hadamard type inequalities for operator m-convex functions in Hilbert space," Journal of New Theory, vol. 5, pp. 80-91, 2015.

V. Darvish, S. S. Dragomir, H. M. Nazari, and A. Taghavi, "Some inequalities associated with the Hermite-Hadamard inequalities for operator h-convex functions," Acta Et Commentationes Universitatis Tartuensis De Mathematica, vol. 21, no. 2, 2017.

T. Lara, N. Merentes, Z. páles, and E. Rosales, "On m-convexity of set-valued functions," Advanced in Operator Theory, vol. 4, no. 4, pp. 767-783, 2019.

S. S. Dragomir, "Hermite–Hadamard’s type inequalities for operator convex functions," Applied Mathematics and Computation, vol. 218, pp. 766-772, Elsevier, 2011.

T. Ando, "Trace-inequalities and matrix-convex functions," Fixed Point Theory and Applications, vol. 2010, Id. 241908, Hindawi, 2010.

A. Pinkus, "The Weierstrass approximation theorems," Surveys in Approximation Theory, vol. 1, pp. 1-37, 2004.




DOI: https://doi.org/10.18860/cauchy.v10i1.32099

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