Skip to main content
Log in

On a Quantitative Theory of Limits: Estimating the Speed of Convergence

  • Research Paper
  • Published:
Fractional Calculus and Applied Analysis Aims and scope Submit manuscript

Abstract

The classical “ε-δ” definition of limits is of little use to quantitative purposes, as is needed, for instance, for computational and applied mathematics. Things change whenever a realistic and computable estimate of the function δ(ε) is available. This may be the case for Lipschitz continuous and Hölder continuous functions, or more generally for functions admitting of a modulus of continuity. This, provided that estimates for first derivatives, fractional derivatives, or the modulus of continuity might be obtained. Some examples are given.

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

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. D. Bambusi, N.N. Nekhoroshev, Long time stability in perturbations of completely resonant PDE’s. Symmetry and perturbation theory. Acta Appl. Math. 70, Nos 1-3, (2002), 1–22.

    Article  MathSciNet  Google Scholar 

  2. K. Diethelm, The Analysis of Fractional Differential Equations.. Springer, Berlin (2010).

    Book  Google Scholar 

  3. K. Diethelm, The mean value theorems and a Nagumo-type uniqueness theorem for Caputo’s fractional calculus. Fract. Calc. Appl. Anal. 15, No 2 (2012), 304–313; DOI: 10.2478/s13540-012-0022-3; https://www.degruyter.com/view/journals/fca/15/2/fca.15.issue-2.xml/view/journals/fca/15/2/fca.15.issue-2.xml; Erratum: The mean value theorems and a Nagumo-type uniqueness theorem for Caputo’s fractional calculus, Fract. Calc. Appl. Anal. 20, No 6 (2017), 1567–1570; DOI: 10.1515/fca-2017-0082; https://www.degruyter.com/view/journals/fca/20/6/fca.20.issue-6.xml/view/journals/fca/20/6/fca.20.issue-6.xml.

    Article  MathSciNet  Google Scholar 

  4. A.V. Efimov, Modulus of continuity. Encyclopaedia of Mathematics, Springer, 2001, (ISBN 1-4020-0609-8); http://eom.springer.de/c/c025580.htm.

    Google Scholar 

  5. I. Ekeland, R. Temam, Convex Analysis and Variational Problems.. North-Holland American Elsevier, Amsterdam and New York (1976).

    MATH  Google Scholar 

  6. S.G. Gal, Calculus of the modulus of continuity for nonconcave functions and applications. Calcolo 27, Nos 3-4, (1990), 195–202.

    Article  MathSciNet  Google Scholar 

  7. J.A. Gallegos, M.A. Duarte-Mermoud, Boundedness and convergence on fractional systems. J. Comput. Appl. Math. 296 (2016), 815–826.

    Article  MathSciNet  Google Scholar 

  8. R. Garrappa, E. Kaslik, M. Popolizio, Evaluation of fractional integrals and derivatives of elementary functions: Overview and tutorial. Mathematics, Open Access (MDPI) 7 (2019), # 407, 21pp.; doi: 10.3390/math7050407; https://www.mdpi.com/journal/mathematics/journal/mathematics.

  9. M. Guzzo, E. Lega, The Nekhoroshev theorem and the observation of long-term diffusion in hamiltonian systems. Regul. Chaotic Dyn. 21, No 6 (2016), 707–719.

    Article  MathSciNet  Google Scholar 

  10. G.H. Hardy, J.E. Littlewood, Some properties of fractional integrals, I. In: Collected Papers of G.H. Hardy, Vol. 1, Ed. by the London Math. Soc., Clarendon Press, Oxford, 1966, 565–606.

    MATH  Google Scholar 

  11. A. Iouditski, Lecture 3. Convex Functions.; https://ljk.imag.fr/membres/Anatoli.Iouditski/optimisation-convexe.htm/membres/Anatoli.Iouditski/optimisation-convexe.htm.

  12. M. Kac, G.-C. Rota, J.T. Schwartz, Discrete Thoughts. Essays on Mathematics, Science and Philosophy.. Birkhäuser, Boston, 1992; 2nd Ed. 2008.

    MATH  Google Scholar 

  13. N.N. Nekhoroshev, The behavior of Hamiltonian systems that are close to integrable ones (In Russian). Funkcional Anal. i Priložen. 5, No 4 (1971), 82–83; MR0294813; Engl. version: Behavior of Hamiltonian systems close to integrable. Functional Analysis and Its Applications 5, No 4 (1971), 338–339.

    Article  Google Scholar 

  14. Z.M. Odibat, N.T. Shawagfeh, Generalized Taylor’s formula. Appl. Math. Comput. 186 (2007), 286–293.

    MathSciNet  MATH  Google Scholar 

  15. F.W.J. Olver, Asymptotics and Special Functions. Reprint of the 1974 original [Academic Press, New York]. AKP Classics. A.K. Peters, Wellesley, (1997).

    Book  Google Scholar 

  16. B. Ross, S.G. Samko, E.R. Love, Functions that have no first order derivative might have fractional derivatives of all orders less than one. Real Anal. Exchange 20, No 1 (1994/5), 140–157.

    Article  MathSciNet  Google Scholar 

  17. D.R. Smith, Singular-Perturbation Theory.. Cambridge University Press, Cambridge (1985).

    MATH  Google Scholar 

  18. R. Spigler, M. Vianello, Improved estimates for the derivatives of the O-symbols in view of numerical applications. J. Math. Anal. Appl. 164, No 2 (1992), 480–488.

    Article  MathSciNet  Google Scholar 

  19. S.M. Ulam, Adventures of a Mathematician.. Charles Scribner’s Sons, New York (1976).

    Book  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Renato Spigler.

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Spigler, R. On a Quantitative Theory of Limits: Estimating the Speed of Convergence. Fract Calc Appl Anal 23, 1013–1024 (2020). https://doi.org/10.1515/fca-2020-0053

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1515/fca-2020-0053

MSC 2010

Key Words and Phrases

Navigation