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On Hyperstability of the Two-Variable Jensen Functional Equation on Restricted Domain

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Mathematical Analysis and Applications

Part of the book series: Springer Optimization and Its Applications ((SOIA,volume 154))

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Abstract

We present a method that allows to study approximate solutions to the two-variable Jensen functional equation

$$\displaystyle 2f\Big (\frac {x+z}{2},\frac {y+w}{2}\Big )=f(x,y)+f(z,w) $$

on a restricted domain. Namely, we show that (under some weak natural assumptions) functions that satisfy the equation approximately (in some sense) must be actually solutions to it. The method is based on a quite recent fixed point theorem in some functions spaces and can be applied to various similar equations in many variables. Our outcomes are connected with the well-known issues of Ulam stability and hyperstability.

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References

  1. M.R. Abdollahpour, R. Aghayari, M. Th. Rassias, Hyers-Ulam stability of associated Laguerre differential equations in a subclass of analytic functions. J. Math. Anal. Appl. 437(1), 605–612 (2016)

    Article  MathSciNet  Google Scholar 

  2. A. Aghajani, F. Zahedi, General solution and generalized Hyers-Ulam stability of a two-variable Jensen functional equation. Math. Sci. 7(45) (2013). https://doi.org/10.1186/2251-7456-7-45

    Article  MathSciNet  Google Scholar 

  3. T. Aoki, On the stability of the linear transformation in Banach spaces. J. Math. Soc. Jpn. 2, 64–66 (1950)

    Article  MathSciNet  Google Scholar 

  4. J.H. Bae, W.G. Park, On the solution of a bi-Jensen functional equation and its stability. Bull. Korean Math. Soc. 43, 499–507 (2006)

    Article  MathSciNet  Google Scholar 

  5. A. Bahyrycz, M. Piszczek, Hyperstability of the Jensen functional equation. Acta Math. Hungar. 142, 353–365 (2014)

    Article  MathSciNet  Google Scholar 

  6. D.G. Bourgin, Approximately isometric and multiplicative transformations on continuous function rings. Duke Math. J. 16, 385–397 (1949)

    Article  MathSciNet  Google Scholar 

  7. D.G. Bourgin, Classes of transformations and bordering transformations. Bull. Am. Math. Soc. 57, 223–237 (1951)

    Article  MathSciNet  Google Scholar 

  8. J. Brzdek, Hyperstability of the Cauchy equation on restricted domains. Acta Math. Hungar. 141(1–2), 58–67 (2013)

    Article  MathSciNet  Google Scholar 

  9. J. Brzdek, Remarks on hyperstability of the Cauchy equation. Aequations Math. 86, 255–267 (2013)

    Article  MathSciNet  Google Scholar 

  10. J. Brzdek, A hyperstability result for the Cauchy equation. Bull. Aust. Math. Soc. 89, 33–40 (2014)

    Article  MathSciNet  Google Scholar 

  11. J. Brzdek, K. Ciepliński, Hyperstability and superstability. Abstr. Appl. Anal. 2013 (2013). Article ID 401756, 13 pp.

    Google Scholar 

  12. J. Brzdek, J. Chudziak, Z. Páles, A fixed point approach to stability of functional equations. Nonlinear Anal. 74, 6728–6732 (2011)

    Article  MathSciNet  Google Scholar 

  13. J. Brzdek, W. Fechner, M.S. Moslehian, J. Sikorska, Recent developments of the conditional stability of the homomorphism equation. Banach J. Math. Anal. 9, 278–327 (2015)

    Article  MathSciNet  Google Scholar 

  14. J. Brzdek, K. Ciepliński, Th.M. Rassias (eds.), Developments in Functional Equations and Related Topics (Springer, New York, 2017)

    Google Scholar 

  15. Y.J. Cho, Th.M. Rassias, R. Saadati, Stability of Functional Equations in Random Normed Spaces (Springer, New York, 2013)

    Book  Google Scholar 

  16. Y.J. Cho, C. Park, Th.M. Rassias, R. Saadati, Stability of Functional Equations in Banach Algebras (Springer, New York, 2015)

    Book  Google Scholar 

  17. Iz. EL-Fassi, On a new type of hyperstability for radical cubic functional equation in non- Archimedean metric spaces. Results Math. 72, 991–1005 (2017)

    Article  MathSciNet  Google Scholar 

  18. Iz. El-Fassi, Approximate solution of radical quartic functional equation related to additive mapping in 2-Banach spaces. J. Math. Anal. Appl. 455, 2001–2013 (2017)

    Google Scholar 

  19. Iz. EL-Fassi, S. Kabbaj, On the hyperstability of a Cauchy-Jensen type functional equation in Banach spaces. Proyecciones J. Math. 34, 359–375 (2015)

    Google Scholar 

  20. Iz. EL-Fassi, S. Kabbaj, A. Charifi, Hyperstability of Cauchy-Jensen functional equations. Indagationes Math. 27, 855–867 (2016)

    Google Scholar 

  21. Iz. El-Fassi, J. Brzdek, A. Chahbi, S. Kabbaj, On hyperstability of the biadditive functional equation. Acta Math. Sci. 37B(6), 1727–1739 (2017)

    Google Scholar 

  22. Z. Gajda, On stability of additive mappings. Int. J. Math. Math. Sci. 14, 431–434 (1991)

    Article  MathSciNet  Google Scholar 

  23. E. Gselmann, Hyperstability of a functional equation. Acta Math. Hungar. 124, 179–188 (2009)

    Article  MathSciNet  Google Scholar 

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

    Article  MathSciNet  Google Scholar 

  25. D.H. Hyers, Th.M. Rassias, Approximate homomorphisms. Aequat. Math. 44, 125–153 (1992)

    Article  MathSciNet  Google Scholar 

  26. G. Isac, Th.M. Rassias, On the Hyers - Ulam stability of ψ- additive mappings. J. Approx. Theory 72, 131–137 (1993)

    Article  MathSciNet  Google Scholar 

  27. K.W. Jun, M.H. Han, Y.H. Lee, On the Hyers-Ulam-Rassias stability of the bi-Jensen functional equation. Kyungpook Math. J. 48, 705–720 (2008)

    Article  MathSciNet  Google Scholar 

  28. K.W. Jun, Y.H. Lee, J.H. Oh, On the Rassias stability of a bi-Jensen functional equation. J. Math. Inequalities 2, 363–375 (2008)

    Article  MathSciNet  Google Scholar 

  29. S.-M. Jung, Hyers-Ulam-Rassias Stability of Functional Equations in Nonlinear Analysis (Springer, New York, 2011)

    Book  Google Scholar 

  30. Pl. Kannappan, Functional Equations and Inequalities with Applications (Springer, New York, 2009)

    Google Scholar 

  31. Z. Kominek, On a local stability of the Jensen functional equation. Demonstratio Math. 22, 499–507 (1989)

    MathSciNet  MATH  Google Scholar 

  32. Y.-H. Lee, On the stability of the monomial functional equation. Bull. Korean Math. Soc. 45, 397–403 (2008)

    Article  MathSciNet  Google Scholar 

  33. G. Maksa, Z. Páles, Hyperstability of a class of linear functional equations. Acta Math. 17, 107– 112 (2001)

    MathSciNet  MATH  Google Scholar 

  34. C. Mortici, M.Th. Rassias, S.-M. Jung, On the stability of a functional equation associated with the Fibonacci numbers. Abstr. Appl. Anal. (2014). Art. ID 546046, 6 pp.

    Google Scholar 

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

    Article  MathSciNet  Google Scholar 

  36. Th.M. Rassias, On a modified Hyers-Ulam sequence. J. Math. Anal. Appl. 158, 106–113 (1991)

    Article  MathSciNet  Google Scholar 

  37. Th.M. Rassias, J. Brzdek (eds.), Functional Equations in Mathematical Analysis (Springer, New York, 2012)

    Google Scholar 

  38. Th.M. Rassias, P. Semrl, On the behavior of mappings which do not satisfy Hyers-Ulam stability. Proc. Am. Math. Soc. 114, 989–993 (1992)

    Article  MathSciNet  Google Scholar 

  39. S.M. Ulam, Problems in Modern Mathematics, Chapter IV, Science Editions (Wiley, New York, 1960)

    Google Scholar 

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EL-Fassi, Ii. (2019). On Hyperstability of the Two-Variable Jensen Functional Equation on Restricted Domain. In: Rassias, T., Pardalos, P. (eds) Mathematical Analysis and Applications. Springer Optimization and Its Applications, vol 154. Springer, Cham. https://doi.org/10.1007/978-3-030-31339-5_5

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