Skip to main content

D’Alembert’s Functional Equation and Superstability Problem in Hypergroups

  • Chapter
  • First Online:
Handbook of Functional Equations

Part of the book series: Springer Optimization and Its Applications ((SOIA,volume 96))

Abstract

Our main goal is to determine the continuous and bounded complex valued solutions of the functional equation

$$ \langle \delta_{x}\ast \delta_{y},g\rangle +\langle \delta_{x}\ast \delta_{\check{y}},g\rangle =2~g(x)g(y),\;x,y\in X,$$

where X is a hypergroup. The solutions are expressed in terms of 2 -dimensional representations of X. The papers of Davison [10] and Stetkaer [25, 26] are the essential motivation for this first part of the present work and the methods used here are closely related to and inspired by those in [10, 25, 26]. In addition, superstability problem for this functional equation on any hypergroup and without any condition on f is considered.

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

Access this chapter

eBook
USD 19.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 29.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 29.99
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. Aoki, T.: On the stability of the linear transformation in Banach spaces. J. Math. Soc. Jpn. 2, 44–66 (1950)

    Article  Google Scholar 

  2. Badora, R.: On Hyers–Ulam stability of Wilson’s functional equation. Aeq. Math. 60, 211–218 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  3. Baker, J.A.: The stability of the cosine equation. Proc. Am. Math. Soc. 80, 411±416 (1980)

    Article  Google Scholar 

  4. Baker, J.A., Lawrence, J., Zorzitto, F.: The stability of the equation \(f(x+y)=f(x)f(y)\). Proc. Am. Math. Soc. 74, 242–246 (1979)

    MATH  MathSciNet  Google Scholar 

  5. Bouikhalene, B.: On Hyers–Ulam stability of generalised Wilson’s equations, J. Inequal. Pure Appl. Math. 5(4), (2004), Article 100.

    Google Scholar 

  6. Bloom, W.R., Hayer, H.: Harmonic analysis of probability measures on hypergroups, Berlin-New York, 1995

    Google Scholar 

  7. Bourbaki, N.: Eléments de Mathématiques. Livre II. Algèbre, Hermann 1958

    Google Scholar 

  8. Corovei, I.: The cosine functional equation on nilpotent groups. Aeq. Math.15, 99–106 (1977)

    Article  MATH  MathSciNet  Google Scholar 

  9. Corovei, I.: The functional equation\(f(xy)+f(yx)+f(xy-1)+f(y-1x)=4f(x)f(y)\) for nilpotent groups., (Romanian, English summary). Bul. Ştiinţ. Instit. Politehn. Cluj-Napoca Ser. Mat.-Fiz.-Mec Apl. 20, 25–28 (1977)

    MathSciNet  Google Scholar 

  10. Davison, T.: D’Alembert’s functional equation on topological monoids.. Publ. Math. Debr. 75/1–2, 41–66 (2009)

    MathSciNet  Google Scholar 

  11. Elqorachi, E., Akkouchi, M.: The superstability of the generalized d’Alembert functional equation. Georgian Math. J. 10(3), 503–508 (2003)

    MATH  MathSciNet  Google Scholar 

  12. Hyers, D.H.: On the stability of the linear functional equation.. Proc. Natl. Acad. Sci. U.S.A. 27, 222–224 (1941)

    Article  MathSciNet  Google Scholar 

  13. Hyers, D.H., Isac, G.I., and Rassias, Th. M: Stability of functional equations in several variables. Progress in nonlinear differential equations and their applications, 34. Birkhauser, Boston (1998)

    Book  Google Scholar 

  14. Jewett, R.I.: Spaces with an abstract convolution of measures. Adv. Math. 18, 1–101 (1975)

    Article  MATH  MathSciNet  Google Scholar 

  15. Kannappan, P.: The functional equation\( f(xy)+f(xy-1)=2f(x)f(y)\) for groups. Proc. Am. Math. Soc. 19, 69–74 (1968)

    MATH  MathSciNet  Google Scholar 

  16. Orosz, Á. and Székelyhidi, L. :Moment function on polynomial hypergroups in several variables. Publ. Math. Debr. 65(3–4), 429–438 (2004)

    MATH  Google Scholar 

  17. Orosz, Á. Sine and cosine equation on discrete polynomial hypergroups. Aeq. Math. 72, 225–233 (2006)

    Article  MATH  MathSciNet  Google Scholar 

  18. Rassias, Th. M.: On the stability of linear mapping in Banach spaces. Proc. Am. Math. Soc. 72, 297–300 (1978)

    Article  MATH  Google Scholar 

  19. Roukbi, A., Zeglami, D.: D’Alembert’s functional equations on hypergroups Adv. Pure Appl. Math. 2, 147–166 (2011)

    Article  MATH  MathSciNet  Google Scholar 

  20. Roukbi, A., Zeglami, D., Kabbaj, S.: Hyers–Ulam stability of Winson’s functional equation. Math. Sci. Adv. Appl. 22, 16–26 (2013)

    Google Scholar 

  21. Sinopoulos, P.: Functional equations on semigroups. Aeq. Math. 59, 255–261 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  22. Stetk\aer, H.: Functional equation on abelian groups with involution. Aeq. Math. 54, 144–172 (1997)

    Article  Google Scholar 

  23. Stetk\aer, H.: D’Alembert’s functional equations on metabelian groups. Aeq. Math. 59, 306–320 (2000)

    Article  Google Scholar 

  24. Stetk\aer, H.: DAlembert’s and Wilson’s functional equations on step 2 nilpotent groups. Aeq. Math. 67, 241–262 (2004)

    Google Scholar 

  25. Stetk\aer, H.: Trigonometric functionals equations on groups, Manuscript presented at a talk during the first Spring School Mehdia / CNG, Kenitra, Morocco, April 2009

    Google Scholar 

  26. Stetkær, H., Functional Equations on Groups, World Scientic, Hackensack, 2013.

    Google Scholar 

  27. Székelyhidi, L.: Functional equations on hypergroups, in: Functional equations, Inequalities and applications, Rassias, Th. M. (ed.), Kluwer, Boston,, 2003, 167–181.

    Google Scholar 

  28. Székelyhidi, L.: Functional equations on topological Sturm-Liouville hypergroups.Math. Pannonica 17/2 (2006), 169–182.

    Google Scholar 

  29. Székelyhidi, L.: On a theorem of Baker, Lawrence and Zorzitto. Proc. Am. Math. Soc. 84, 95–96 (1982)

    Article  MATH  Google Scholar 

  30. Wilson, W.H.: On a certain related functional equations. Proc. Am. Soc. 26, 300–312(1919–1920)

    Google Scholar 

  31. Zeglami, D., Kabbaj, S., Charifi, A., Roukbi, A.: \(\mu -\)trigonometric functional equations and stability problem on hypergroups. Functional Equations in Mathematical Analysis 2011, (26) 337–358. Springer optimization and its applications 52, doi:10007/978-1-46-14-0055-4_26

    Google Scholar 

  32. Zeglami, D., Roukbi, A., and Kabbaj, S., Hyers–Ulam stability of generalized Wilson’s and d'Alembert’s functional equations, Afr. Mat. (2013), DOI 10.1007/s13370--013-0199-6.

    Google Scholar 

  33. Zeglami, D., Kabbaj, S., and Roukbi, A., Superstability of a generalization of the cosine equation, British J. Math. Comput. Sci. 4 (2014), no. 5, 719-734.

    Google Scholar 

  34. Zeglami, D., The superstability of a variant of Wilson’s functional equations on an arbitrary group, Afr. Mat. (2014), DOI 10.1007/s13370-014-0229-z.

    Google Scholar 

  35. Zeglami, D., Kabbaj, S., and Charifi A., On the stability of the generalized mixed trigonometric functional equations, Adv. Pure Appl. Math. 2014, to apper.

    Google Scholar 

  36. Zeglami, D., Roukbi, A., Kabbaj, S., Rassias, Th. M., Hyers-Ulam stability of Wilson’s functional equation on hypergroups. International J. of Scientific & Innovative Math. Research, (2013) 1(1), 66–80.

    Google Scholar 

Download references

Acknowledgement

Our sincere regards and gratitude go to Professor Henrik Stetkær for fruitful discussions and for sending us some of his papers on functional equations.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to D. Zeglami .

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

Zeglami, D., Roukbi, A., Rassias, T. (2014). D’Alembert’s Functional Equation and Superstability Problem in Hypergroups. In: Rassias, T. (eds) Handbook of Functional Equations. Springer Optimization and Its Applications, vol 96. Springer, New York, NY. https://doi.org/10.1007/978-1-4939-1286-5_17

Download citation

Publish with us

Policies and ethics