Abstract
This survey deals with functions called γ-quasiconvex functions and their relations to convexity and superquadracity. For γ-quasiconvex functions and for superquadratic functions, we get analogs of inequalities satisfied by convex functions and we get refinements for those convex functions which are also γ-quasiconvex as well as superquadratic. We show in which cases the refinements by γ-quasiconvex functions are better than those obtained by superquadratic functions and convex functions. The power functions defined on x ≥ 0 where the power is greater or equal to two are examples of convex, quasiconvex, and superquadratic functions.
In Honor of Constantin Carathéodory
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References
Abramovich, S., Persson, L.E.: Some new scales of refined Hardy type inequalities via functions related to superquadracity. Math. Inequal. Appl. 16, 679–695 (2013)
Abramovich, S., Persson, L.E.: Some new refined Hardy type inequalities with breaking points p = 2 or p = 3. In: Proceedings of the IWOTA 2011, Operator Theory: Advances and Applications, vol. 236, pp. 1–10. Birkhäuser/Springer, Basel/Berlin (2014)
Abramovich, S., Persson, L.E.: Inequalities for averages of quasiconvex and superquadratic functions. Math. Inequal. Appl. 19 (2), 535–550 (2016)
Abramovich, S., Jameson, G., Sinnamon, G.: Inequalities for averages of convex and superquadratic functions. J. Inequal. Pure Appl. Math. 5 (4), Article 91 (2004)
Abramovich, S., Jameson, G., Sinnamon, G.: Refining Jensen’s inequality. Bull. Math. Soc. Sci. Math. Roumanie (N.S.) 47 (95), 3–14 (2004)
Abramovich, S., Bakula M.K., Matić M., Pečarić, J.: A variant of Jensen-Steffensen’s inequality and quazi arithmetic means. J. Math. Anal. Appl. 307, 370–386 (2005)
Abramovich, S., Krulic, K., Person, L.-E., Pečarić, J.: Some new refined Hardy type inequalities with general kernels via superquadratic and subquadratic functions. Aequationes Math. 79 (1), 157–172 (2010) (On line March 2010)
Abramovich, S., Persson, L.E., Samko, S.: Some new scales of refined Hardy type inequalities. Math. Inequal. Appl. 17, 1105–1114 (2014)
Abramovich, S., Persson, L.E., Samko, S.: On γ-quasiconvexity, superquadracity and two-sided reversed Jensen type inequalities. Math. Inequal. Appl. 18 (2), 615–628 (2015)
Anwar, M., Jakšetić, J., Pečarić, J., Rehman, A.: Exponential convexity, positive semi-definite matrices and fundamental inequalities. J. Math. Inequal. 4 (2), 171–189 (2010)
Banić, S., Varošanec, S.: Functional inequalities for superquadratic functions. Int. J. Pure Appl. Math. 43 (4), 5037–549 (2008)
Banić, S., Pečarić, J., Varošanec, S.: Superquadratic functions and refinements of some classical inequalities. J. Korean Math. Soc. 45, 513–525 (2008)
Bibi, R., Bohner, M., Pečarić, J.: Cauchy type means and exponential and logarithmic convexity for superquadratic functions on time scale. Ann. Funct. Anal. 6 (1), 59–83 (2015)
Gilányi, A., Troczka-Pawelec, K.: Regularity of weakly subquadratic functions. J. Math. Anal. Appl. 382, 814–821 (2011)
Gilányi, A., Kézi, C.G., Troczka-Pawelec, K.: On two different concept of superquadracity. Inequalities and Applications, pp. 209–215. Birkhauser, Basel (2010)
Hardy, G.H.: Notes on a theorem of Hilbert. Math. Z. 6, 314–317 (1920)
Mitroi, F.-C.: On the Jensen-Steffensen inequality and superquadracity. Anale Universitatii, Oradea, Fasc. Mathematica, Tom XVIII, pp. 269–275 (2011)
Oguntuase, J.A., Persson, L.-E.: Refinement of Hardy’s inequalities via superquadratic and subquadratic functions. J. Math. Anal. Appl. 339, 1305–1312 (2008)
Oguntuase, J.A., Persson, L.-E.: Hardy type inequalities via convexity-the journey so far. Aust. J. Math. Anal. Appl. 7 (2), Art. 18, 19 (2010)
Oguntuase, J.A., Persson, L.E.: Time scale Hardy type inequalities via superquadracity. Ann. Funct. Anal. 5 (2), 61–73 (2014)
Oguntuase, J.A., Popoola, B.A.: Refinement of Hardy’s inequalities involving many functions via superquadratic functions. An. Ştiinţ. Univ. Al. I. Cuza Iaşi. Mat. (N.S.) 57 (2), 271–283 (2011)
Oguntuase, J.A., Persson, L.E., Essel, E.K., Popoola, B.A.: Refined multidimensional Hardy-type inequalities via superquadracity. Banach J. Math. Anal. 2 (2), 129–139 (2008)
Pečarić, J., Proschan, F., Tong, Y.L.: Convex Functions, Partial Orderings and Statistical Applications. Academic, Boston (1992)
Persson, L.E., Samko, N.: What should have happened if Hardy had discovered this? J. Inequal. Appl. 2012:29, 11 pp (2012)
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Abramovich, S. (2016). Applications of Quasiconvexity. In: Pardalos, P., Rassias, T. (eds) Contributions in Mathematics and Engineering. Springer, Cham. https://doi.org/10.1007/978-3-319-31317-7_1
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DOI: https://doi.org/10.1007/978-3-319-31317-7_1
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