Skip to main content

On Strongly Convex Functions and Related Classes of Functions

  • Chapter
  • First Online:
Handbook of Functional Equations

Part of the book series: Springer Optimization and Its Applications ((SOIA,volume 95))

Abstract

Many results on strongly convex functions and related classes of functions obtained in the last few years are collected in the paper. In particular, Jensen, Hermite–Hadamard- and Fejér-type inequalities for strongly convex functions are presented. Counterparts of the classical Bernstain–Doetsch and Sierpiński theorems for strongly midconvex functions are given. New characterizations of inner product spaces involving strong convexity are obtained. A representation of strongly Wright-convex functions and a characterization of functions generating strongly Schur-convex sums are presented. Strongly n-convex and Jensen n-convex functions are investigated. Finally, a relationship between strong convexity and generalized convexity in the sense of Beckenbach is established.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 84.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 109.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 109.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. Aczél, J., Dhombres, J.: Functional equations in several variables. In: Doran, R., Ismail, M., Lam, T.-Y., Lutwak E. (eds.) Encyclopaedia of Mathemathics and its Applications. Cambridge University Press, Cambridge (1989)

    Google Scholar 

  2. Alsina, C., Sikorska, J., Tomás, M.N.: Norm Derivatives and Characterizations of Inner Product Spaces. World Scientific, Hackensack (2010)

    MATH  Google Scholar 

  3. Amir, D.: Characterizations of Inner Product Spaces, OT, vol. 20. Birkhäuser, Basel (1986)

    Book  Google Scholar 

  4. Angulo, H., Giménez, J., Moros, A.-M., Nikodem, K.: On strongly h-convex functions. Ann. Funct. Anal. 2, 87–93 (2011)

    Article  Google Scholar 

  5. Azócar, A., Nikodem, K., Roa, G.: Féjer-type inequalities for strongly convex functions. Ann. Math. Silesia. Accepted for publication

    Google Scholar 

  6. Azócar, A., Giménez, J., Nikodem, K., Sánchez, J.L.: On strongly midconvex functions. Opusc. Math. 31(1), 15–26 (2011)

    Article  MATH  Google Scholar 

  7. Baron, K., Matkowski, J., Nikodem, K.: A sandwich with convexity. Math. Pannon. 5(1), 139–144 (1994)

    MATH  MathSciNet  Google Scholar 

  8. Beckenbach, E.F.: Generalized convex functions. Bull. Am. Math. Soc. 43, 363–371 (1937)

    Article  MathSciNet  Google Scholar 

  9. Bessenyei, M., Páles, Zs.: Hadamard-type inequalities for generalized convex functions. Math. Inequal. Appl. 6(3), 379–392 (2003)

    MATH  MathSciNet  Google Scholar 

  10. Bessenyei, M., Páles, Zs.: Characterization of convexity via Hadamard’s inequality. Math. Inequal. Appl. 9(1), 53–62 (2006)

    MATH  MathSciNet  Google Scholar 

  11. Ciesielski, Z.: Some properties of convex functions of higher order. Ann. Polon. Math. 7, 1–7 (1959)

    MATH  MathSciNet  Google Scholar 

  12. Daróczy, Z., Páles, Zs.: Convexity with given infinite weight sequences. Stochastica 11, 5–12 (1987)

    MATH  MathSciNet  Google Scholar 

  13. Dragomir, S.S., Fitzpatrik, S.: The Hadamardt’s inequality for s-convex functions in the second sense. Demonstr. Math. 32, 687–696 (1999)

    MATH  Google Scholar 

  14. Dragomir, S.S., Pearce, C.E.M.: Selected Topics on Hermite–Hadamard Inequalities and Applications. RGMIA Monographs, Victoria University (2002). http://rgmia.vu.edu.au/monographs/

    Google Scholar 

  15. Dragomir, S.S., Pe\ucarić, J., Persson, L.E.: Some inequalities of Hadamard type. Soochow J. Math. 21, 335–341 (1995)

    Google Scholar 

  16. Fejér, L.: Über die Fourierreihen, II. Math. Naturwiss, Anz. Ungar. Wiss. 24, 369–390 (1906). (In Hungarian)

    Google Scholar 

  17. Ger, R.: Convex functions of higher order in Euclidean spaces. Ann. Polon. Math. 25, 293–302 (1972)

    MATH  MathSciNet  Google Scholar 

  18. Ger, R., Nikodem, K.: Strongly convex functions of higher order. Nonlinear Anal. 74, 661–665 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  19. Hardy, G.H., Littlewood, J.E., Pólya, G.: AQ4Inequalities. Cambridge University Press (1952)

    Google Scholar 

  20. Hiriart-Urruty, J.-B., Lemaréchal, C.: Fundamentals of Convex Analysis. Springer, Berlin (2001)

    Book  MATH  Google Scholar 

  21. Hyers, D.H., Ulam, S.M.: Approximately convex functions. Proc. Am. Math. Soc. 3, 821–828 (1952)

    Article  MATH  MathSciNet  Google Scholar 

  22. Jovanovič, M.V.: A note on strongly convex and strongly quasiconvex functions. Math. Notes 60(5), 778–779 (1996)

    MathSciNet  Google Scholar 

  23. Karamata, J.: Sur une inégalité rélative aux fonctions convexes. Publ. Math. Univ. Belgrad. 1, 145–148 (1932)

    Google Scholar 

  24. Kominek, Z.: On additive and convex functionals. Radovi Mat. 3, 267–279 (1987)

    MATH  MathSciNet  Google Scholar 

  25. Kominek, Z.: On a problem of K. Nikodem. Arch. Math. 50, 287–288 (1988)

    Article  MATH  MathSciNet  Google Scholar 

  26. König, H.: On the abstract Hahn–Banach theorem due to Rodé. Aequ. Math. 34, 89–95 (1987)

    Article  MATH  Google Scholar 

  27. Kuczma, M.: An Introduction to the Theory of Functional Equations and Inequalities. Cauchy’s Equation and Jensen’s Inequality. PWN-Uniwersytet Śl S´ la˛ski, Warszawa (1985). (Second Edition: Birkhäuser, Basel–Boston–Berlin, 2009)

    Google Scholar 

  28. Kuhn, N.: A note on t-convex functions, general inequalities, 4 (Oberwolfach, 1983). In: Walter, W. (ed.) International Series of Numerical Mathematics, vol. 71, Birkhäuser, Basel, pp. 269–276 (1984)

    Google Scholar 

  29. Marshall, A.W., Olkin, I.: Inequalities: Theory of Majorization and Its Applications, Mathematics in Science and Engineering 143. Academic Press Inc., New York (1979)

    Google Scholar 

  30. Merentes, N., Nikodem, K.: Remarks on strongly convex functions. Aequ. Math. 80, 193–199 (2010)

    Article  MATH  MathSciNet  Google Scholar 

  31. Merentes, N., Nikodem, K., Rivas, S.: Remarks on strongly Wright-convex functions. Ann. Polon. Math. 102(3), 271–278 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  32. Montrucchio, L. Lipschitz continuous policy functions for strongly concave optimization problems. J. Math. Econ. 16, 259–273 (1987)

    Article  MATH  MathSciNet  Google Scholar 

  33. Ng, C.T.: Functions generating Schur-convex sums. General Inequalities 5 (Oberwolfach, 1986). Internat. Ser. Numer. Math. 80, 433–438 (1987). (Birkhäuser Verlag, Basel–Boston)

    Google Scholar 

  34. Ng, C.T.: On midconvex functions with midconcave bounds. Proc. Am. Math. Soc. 102, 538–540 (1988)

    Article  MATH  Google Scholar 

  35. Niculescu, C.P., Persson, L.-E.: Convex Functions and their Applications. A Contemporary Approach, CMS Books in Mathematics, vol. 23. Springer, New York (2006)

    Google Scholar 

  36. Nikodem, K.: Midpoint convex functions majorized by midpoint concave functions. Aequ. Math. 32, 45–51 (1987)

    Article  MATH  MathSciNet  Google Scholar 

  37. Nikodem, K.: On some class of midconvex functions. Ann. Polon. Math. 72, 145–151 (1989)

    MathSciNet  Google Scholar 

  38. Nikodem, K.: On the support of midconvex operators. Aequ. Math. 42, 182–189 (1991)

    Article  MATH  MathSciNet  Google Scholar 

  39. Nikodem, K., Páles, Zs.: Generalized convexity and separation theorems. J. Conv. Anal. 14(2), 239–247 (2007)

    MATH  Google Scholar 

  40. Nikodem, K., Páles, Zs.: Characterizations of inner product spaces by strongly convex functions. Banach J. Math. Anal. 5(1), 83–87 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  41. Nikodem, K., Rajba, T., W\c asowicz, Sz.: Functions generating strongly Schur-convex sums. In: Bandle, C., et al. (eds.) Inequalities andAQ5 Applications 2010, International Series of Numerical Mathematics 161, pp. 175–182. Birkhäuser, Basel (2012). (© Springer Basel 2012. doi:10.1007/978-3-0348-0249-9_13)

    Google Scholar 

  42. Pečarić, J.E., Proschan, F., Tong, Y.L.: Convex Functions, Partial Orderings, and Statistical Applications. Academic Press Inc., Boston (1992)

    MATH  Google Scholar 

  43. Polovinkin, E.S.: Strongly convex analysis. Sb. Math. 187(2), 259–286 (1996)

    Article  MATH  MathSciNet  Google Scholar 

  44. Polyak, B.T.: Existence theorems and convergence of minimizing sequences in extremum problems with restrictions. Sov. Math. Dokl. 7, 72–75 (1966)

    Google Scholar 

  45. Popoviciu, T.: Les Fonctions Convexes. Hermann et Cie, Paris (1944)

    MATH  Google Scholar 

  46. Rajba, T., Wa˛sowicz, S.: Probabilistic characterization of strong convexity. Opusc. Math. 31,806 97–103 (2011)

    Google Scholar 

  47. Rassias, Th.M.: New characterizations of inner product spaces. Bull. Sci. Math. 108, 95–99 (1984)

    MATH  MathSciNet  Google Scholar 

  48. Roberts, A.W., Varberg, D.E.: Convex Functions. Academic Press, New York (1973)

    MATH  Google Scholar 

  49. Rodé, G.: Eine abstrakte Version des Satzes von Hahn–Banach. Arch. Math. 31, 474–481 (1978)

    Article  MATH  Google Scholar 

  50. Schur, I.: Über eine Klasse von Mittelbildungen mit Anwendungen auf die Determinantentheorie. Sitzungsber. Berl. Math. Ges. 22, 9–20 (1923)

    Google Scholar 

  51. Sarikaya, M.Z., Saglam, A., Yildirim, H.: On some Hadamard-type inequalities for h-convex functions. J. Math. Inequal. 2, 335–341 (2008)

    Article  MATH  MathSciNet  Google Scholar 

  52. Tornheim, L.: On n-parameter families of functions and associated convex functions. Trans. Am. Math. Soc. 69, 457–467 (1950)

    MATH  MathSciNet  Google Scholar 

  53. Varo\usanec, S.: On h-convexity. J. Math. Anal. Appl. 326, 303–311 (2007)

    Google Scholar 

  54. Vial, J.P.: Strong convexity of sets and functions. J. Math. Econ. 9, 187–205 (1982)

    Article  MATH  MathSciNet  Google Scholar 

  55. Vial, J.P.: Strong and weak convexity of sets and functions. Math. Oper. Res. 8, 231–259 (1983)

    Article  MATH  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Kazimierz Nikodem .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2014 Springer Science+Business Media, LLC

About this chapter

Cite this chapter

Nikodem, K. (2014). On Strongly Convex Functions and Related Classes of Functions. In: Rassias, T. (eds) Handbook of Functional Equations. Springer Optimization and Its Applications, vol 95. Springer, New York, NY. https://doi.org/10.1007/978-1-4939-1246-9_16

Download citation

Publish with us

Policies and ethics