Abstract
We study some properties enjoyed by convex functions. Among other results, we show some nontrivial inequalities among real numbers, and we give an improvement of the reverse triangle inequality in the particular case where three aligned points are considered in a normed space.
References
- R. M. Aron, L. Bernal-González, D. Pellegrino, J. B. Seoane-Sepúlveda: Lineability: The Search for Linearity in Mathematics, Monographs and Research Notes in Mathematics, Chapman & Hall, Boca Raton (2016).https://doi.org/10.1201/b19277Google Scholar
- R. M. Aron, V. I. Gurariy, J. B. Seoane-Sepúlveda: Lineability and spaceability of sets of functions on R, Proc. Amer. Math. Soc. 133(3) (2005) 795–803.https://doi.org/10.1090/S0002-9939-04-07533-1Google Scholar
- F. Bastin, J. A. Conejero, C. Esser, J. B. Seoane-Sepúlveda: Algebrability and nowhere Gevrey differentiability, Israel J. Math. 205(1) (2015) 127–143.https://doi.org/10.1007/s11856-014-1104-1Google Scholar
- L. Bernal-González: The algebraic size of the family of injective operators, Open Math. 15 (2017) 13–20.https://doi.org/10.1515/math-2017-0005Google Scholar
- L. Bernal-González, M. Ordóñez Cabrera: Lineability criteria, with applications, J. Funct. Anal. 266(6) (2014) 3997–4025.https://doi.org/10.1016/j.jfa.2013.11.014Google Scholar
- L. Bernal-González, D. Pellegrino, J. B. Seoane-Sepúlveda: Linear subsets of nonlinear sets in topological vector spaces, Bull. Amer. Math. Soc. (N.S.) 51(1) (2014) 71–130.https://doi.org/10.1090/S0273-0979-2013-01421-6Google Scholar
- P. E. Ezimadu: A characterization of uniformly convex functions, J. Math. Sci. (Dattapukur) 25(1) (2014) 49–57.Google Scholar
- M. Fujii, Y. O. Kim, R. Nakamoto: A characterization of convex functions and its application to operator monotone functions, Banach J. Math. Anal. 8(2) (2014) 118–123.https://doi.org/10.15352/bjma/1396640056Google Scholar
- J. L. Gámez-Merino, J. B. Seoane-Sepúlveda: An undecidable case of lineability in RR, J. Math. Anal. Appl. 401(2) (2013) 959–962.https://doi.org/10.1016/j.jmaa.2012.10.067Google Scholar
- A. Hantoute, J. E. Martínez-Legaz: Characterization of Lipschitz continuous difference of convex functions, J. Optim. Theory Appl. 159(3) (2013) 673–680.https://doi.org/10.1007/s10957-013-0291-yGoogle Scholar
- J. L. W. V. Jensen: Om konvexe Funktioner og Uligheder merrem Middelvaerdier, Nyt Tidsskr. Math. 16 (1905) 49–69.Google Scholar
- J. L. W. V. Jensen: Sur les fonctions convexes et les inegalités entre les valeurs moyennes, Acta Math. 30 (1906) 175–193.https://doi.org/10.1007/BF02418571Google Scholar
- P. Jiménez-Rodríguez, G. A. Muñoz-Fernández, J. B. Seoane-Sepúlveda: Non-Lipschitz functions with bounded gradient and related problems, Linear Algebra Appl. 437(4) (2012) 1174–1181.https://doi.org/10.1016/j.laa.2012.04.010Google Scholar
- Y. C. Li, C. C. Yeh: Some characterizations of convex functions, Comput. Math. Appl. 59(1) (2010) 327–337.https://doi.org/10.1016/j.camwa.2009.05.020Google Scholar
- B. Micherda: A new characterization of convex φ-functions with a parameter, Opuscula Math. 35(2) (2015) 191–197.https://doi.org/10.7494/OpMath.2015.35.2.191Google Scholar
- C. T. Ng: On midconvex functions with midconcave bounds, Proc. Amer. Math. Soc. 102 (1988) 538–540.https://doi.org/10.1090/S0002-9939-1988-0928975-7Google Scholar
- K. Nijodem: Problems and remarks, in: Proc. Internat. Conf. on Functional Equations and Inequalities, Sielpia, Poland, May 27–June 2 (1984).Google Scholar
- D. Puglisi, J. B. Seoane-Sepúlveda: Bounded linear non-absolutely summing operators, J. Math. Anal. Appl. 338(1) (2008) 292–298.https://doi.org/10.1016/j.jmaa.2007.05.029Google Scholar
- A. W. Roberts, D. E. Vaberg: Convex Functions, Pure and Applied Mathematics, a Series of Monographs and Textbooks 57, Academic Press, New York (1973).Google Scholar
- J. B. Seoane-Sepúlveda: Chaos and Lineability of Pathological Phenomena in Analysis, Ph. D. Thesis, Kent State University, ProQuest LLC, Ann Arbor (2006).Google Scholar
- K. L. Teo, X. Q. Yang: A characterization of convex function, Appl. Math. Letters 13 (2000) 27–30.https://doi.org/10.1016/S0893-9659(99)00140-8Google Scholar
- M. Volle, J. B. Hiriart-Urruty: A characterization of essentially strictly convex functions on reflexive Banach spaces, Nonlinear Analysis 75(3) (2012) 1617–1622.https://doi.org/10.1016/j.na.2011.03.056Google Scholar
Suggested citation
Published by Heldermann Verlag, 2019. Rights now held by Banach Press.
