Skip to main content
Log in

The Thomas–Fermi Problem and Solutions of the Emden–Fowler Equation

  • Published:
Computational Mathematics and Mathematical Physics Aims and scope Submit manuscript

Abstract

A two-point boundary value problem is considered for the Emden–Fowler equation, which is a singular nonlinear ordinary differential equation of the second order. Assuming that the exponent in the coefficient of the nonlinear term is rational, new parametric representations are obtained for the solution of the boundary value problem on the half-line and on the interval. For the problem on the half-line, a new efficient formula is given for the first term of the well-known Coulson–March expansion of the solution in a neighborhood of infinity, and generalizations of this representation and its analogues for the inverse of the solution are obtained. For the Thomas–Fermi model of a multielectron atom and a positively charged ion, highly efficient computational algorithms are constructed that solve the problem for an atom (that is, the boundary value problem on the half-line) and find the derivative of this solution with any prescribed accuracy at an arbitrary point of the half-line. The results are based on an analytic property of a special Abel equation of the second kind to which the original Emden–Fowler equation reduces, to be precise, the property of partially passing a modified Painlevé test at a nodal singular point.

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.

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.

Similar content being viewed by others

REFERENCES

  1. E. Fermi, “Un metodo statistico per la determinazione di alcune prioprieta dell’atomo,” Rend. Accad. Naz. Lincei 6, 602–607 (1927).

    Google Scholar 

  2. L. H. Thomas, “The calculations of atomic fields,” Proc. Cambridge Philos. Soc., No. 23, 542–598 (1927).

    Article  Google Scholar 

  3. L. D. Landau and E. M. Lifshitz, Quantum Mechanics: Non-Relativistic Theory (Butterworth-Heinemann, Oxford, 1977; Nauka, Moscow, 1989).

  4. N. H. March, “The Fermi–Thomas theory,” Theory of the Inhomogeneous Electron Gas, Ed. by S. Lunqvist and N. H. March (Plenum, New York, 1983), pp. 9–85.

    Google Scholar 

  5. R. Bellman, Stability Theory of Differential Equations (McGraw-Hill, New York, 1953).

    MATH  Google Scholar 

  6. D. Sansone, Equazioni differenziali nel campo reale (Nicola Zanichelli, Bologna, 1948).

    MATH  Google Scholar 

  7. A. Sommerfeld, “Integrazione asintotica dell’equazione differenziale di Fermi–Thomas,” Rend. R. Accad. Lincei 15, 293–308 (1932).

    MATH  Google Scholar 

  8. S. Flugge, Practical Quantum Mechanics (Springer-Verlag, Berlin, 1971).

    Book  Google Scholar 

  9. E. Hille, “Some aspects of the Fermi–Thomas equation,” J. Anal. Math. 23, 147–170 (1970).

    Article  Google Scholar 

  10. E. B. Baker, “The application of the Fermi–Thomas statistical model to the calculation of potential distribution in positive ions,” Phys. Rev. 36, 630–647 (1930).

    Article  Google Scholar 

  11. C. A. Coulson and N. H. March, “Momenta in atoms using the Fermi–Thomas method,” Proc. Phys. Soc. Sect. A 63 (4), 367–367 (1950).

    Article  Google Scholar 

  12. A. L. Dyshko, M. P. Carpentier, N. B. Konyukhova, and P. M. Lima, “Singular problems for Emden–Fowler-type second-order nonlinear ordinary differential equations,” Comput. Math. Math. Phys. 41 (4), 557–580 (2001).

    MathSciNet  MATH  Google Scholar 

  13. V. Bush and S. H. Caldwell, “Fermi–Thomas equation solution by the differential analyzer,” Phys. Rev. 38 (10), 1898–1902 (1931).

    Article  Google Scholar 

  14. C. Miranda, “Teoremi e metodi per l’integrazione numerica dell' equazione differenziale di Fermi,” Mem. R. Acc. Italia, No. 5, 285–322 (1934).

  15. J. C. Slater and H. M. Krutter, “The Fermi–Thomas method for metals,” Phys. Rev. 47 (7), 559–568 (1935).

    Article  Google Scholar 

  16. R. P. Feynman, N. Metropolis, and E. Teller, “Equations of state of elements based on the generalized Fermi–Thomas theory,” Phys. Rev. 75 (10), 1561–1573 (1949).

    Article  Google Scholar 

  17. S. Kobayashi, T. Matsukuma, S. Nagai, and K. Umeda, “Accurate value of the initial slope of the ordinary TF function,” J. Phys. Soc. Jpn. 10, 759–762 (1955).

    Article  Google Scholar 

  18. H. Krutter, “Numerical integration of the Thomas–Fermi equation from zero to infinity,” J. Comput. Phys. 47 (2), 308–312 (1982).

    Article  Google Scholar 

  19. R. Bellman, “Dynamic programming and the variational solution of the Fermi–Thomas equation,” J. Phys. Soc. Jpn. 12, 1049 (1957).

    Article  Google Scholar 

  20. T. Ikebe and T. Kato, “Application of variational method to the Fermi–Thomas equation,” J. Phys. Soc. Jpn. 12 (2), 201–203 (1957).

    Article  Google Scholar 

  21. R. V. Ramnath, “A new analytical approximation for the Fermi–Thomas model in atomic physics,” J. Math. Anal. Appl. 31 (2), 285–296 (1970).

    Article  MathSciNet  Google Scholar 

  22. I. M. Torrens, Interatomic Potentials (Academic, New York, 1972).

    Book  Google Scholar 

  23. N. Anderson and A. M. Arthurs, “Variational solutions of the Fermi–Thomas equation,” Q. Appl. Math. 39, 127–129 (1981–1982).

    Article  Google Scholar 

  24. M. Desaix, D. Anderson, and M. Lisak, “Variational approach to the Fermi–Thomas equation,” Eur. J. Phys. 25, 699–705 (2004).

    Article  Google Scholar 

  25. M. Oulne, “Variation and series approach to the Fermi–Thomas equation,” Appl. Math. Comput. 218 (2), 303–307 (2011).

    MATH  Google Scholar 

  26. R. C. Flagg, C. D. Luning, and W. L. Perry, “Implementation of new iterative techniques for solutions of Thomas–Fermi and Emden–Fowler equations,” J. Comput. Phys. 38, 396–405 (1980).

    Article  MathSciNet  Google Scholar 

  27. C. M. Bender, K. A. Milton, S. S. Pinsky, and L. M. Simmons, “A new perturbative approach to nonlinear problems,” J. Math. Phys. 30 (7), 1447–1455 (1989).

    Article  MathSciNet  Google Scholar 

  28. K. Tu, “Analytic solution to the Fermi–Thomas and Fermi–Thomas–Dirac–Weizsäcker equations,” J. Math. Phys. 32, 2250–2253 (1991).

    Article  MathSciNet  Google Scholar 

  29. N. A. Zaitsev, I. V. Matyushkin, and D. V. Shamonov, “Numerical solution of the Fermi–Thomas equation for the centrally symmetric atom,” Russ. Microelectron. 33 (5), 303–309 (2004).

    Article  Google Scholar 

  30. A. J. MacLeod, “Chebyshev series solution of the Fermi–Thomas equation,” Comput. Phys. Commun. 67 (3), 389–391 (1992).

    Article  Google Scholar 

  31. K. Parand and M. Shahini, “Rational Chebyshev pseudospectral approach for solving Fermi–Thomas equation,” Phys. Lett. A 373 (2), 210–213 (2009).

    Article  MathSciNet  Google Scholar 

  32. K. Parand, K. Rabiei, and M. Delkhosh, “An efficient numerical method for solving nonlinear Thomas–Fermi equation,” Acta Univ. Sapientiae, Math. 10 (1), 134–151 (2018).

    MATH  Google Scholar 

  33. J. P. Boyd, “Rational Chebyshev series for the Fermi–Thomas function: Endpoint singularities and spectral methods,” J. Comput. Appl. Math. 244, 90–101 (2013).

    Article  MathSciNet  Google Scholar 

  34. J. C. Mason, “Rational approximations to the ordinary Fermi–Thomas function and its derivative,” Proc. Phys. Soc. 84 (3), 357 (1964).

    Article  Google Scholar 

  35. S. Abbasbandy and C. Bervillier, “Analytic continuation of Taylor series and the boundary value problems of some nonlinear ordinary differential equations,” Appl. Math. Comput. 218, 2178–2199 (2011).

    MathSciNet  MATH  Google Scholar 

  36. L. N. Epele, H. Fanchiotti, C. A. García Canal, and J. A. Ponciano, “Padé approximant approach to the Fermi–Thomas problem,” Phys. Rev. A 60, 280–283 (1999).

    Article  Google Scholar 

  37. S. Liao, “An explicit analytic solution to the Fermi–Thomas equation,” Appl. Math. Comput. 144, 495–506 (2003).

    MathSciNet  MATH  Google Scholar 

  38. G. I. Plindov and S. K. Pogrebnaya, “The analytical solution of the Fermi–Thomas equation for a neutral atom,” J. Phys. B 20, 547–550 (1987).

    Article  MathSciNet  Google Scholar 

  39. F. M. Fernandez and J. F. Ogilvie, “Approximate solutions to the Fermi–Thomas equation,” Phys. Rev. A 42 (1), 149–154 (1990).

    Article  Google Scholar 

  40. S. Esposito, “Majorana solution of the Fermi–Thomas equation,” Am. J. Phys. 70 (8), 852–856 (2002).

    Article  Google Scholar 

  41. S. Esposito, “Majorana transformation for differential equations,” Int. J. Theor. Phys. 41 (12), 2417–2426 (2002).

    Article  MathSciNet  Google Scholar 

  42. S. R. Finch, “Mathematical constants II,” Encyclopedia of Mathematics and Its Applications (Cambridge Univ. Press, Cambridge, 2018).

    Google Scholar 

  43. D. E. Panayotounakos and D. C. Kravvaritisb, “Exact analytic solutions of the Abel, Emden–Fowler, and generalized Emden–Fowler nonlinear ODEs,” Nonlinear Anal. Real World Appl. 7 (4), 634–650 (2006).

    Article  MathSciNet  Google Scholar 

  44. D. E. Panayotounakos and N. Sotiropoulos, “Exact analytic solutions of unsolvable classes of first- and second-order nonlinear ODEs (Part II: Emden–Fowler and relative equations),” Appl. Math. Lett. 18 (4), 367–374 (2005).

    Article  MathSciNet  Google Scholar 

  45. E. E. Theotokoglou, T. I. Zarmpoutis, and I. H. Stampouloglou, “Closed-form solutions of the Fermi–Thomas in heavy atoms and the Langmuir–Blodgett in current flow ODEs in mathematical physics,” Math. Probl. Eng. 2015, Article ID 721637 (2015).

    Article  Google Scholar 

  46. S. I. Bezrodnykh and V. I. Vlasov, “The boundary value problem for the simulation of physical fields in a semiconductor diode,” Comput. Math. Math. Phys. 44 (12), 2112–2142 (2004).

    MathSciNet  Google Scholar 

  47. S. V. Pikulin, “The behavior of solutions to a special Abel equation of the second kind near a nodal singular point,” Comput. Math. Math. Phys. 58 (12), 1948–1966 (2018).

    Article  MathSciNet  Google Scholar 

  48. R. M. Conte and M. Musette, The Painlevé Handbook (Springer Science+Business Media, Dordrecht, 2008).

  49. E. Hille, Ordinary Differential Equations in the Complex Domain (Wiley, New York, 1976).

    MATH  Google Scholar 

  50. V. P. Varin, “A solution of the Blasius problem,” Comput. Math. Math. Phys. 54 (6), 1025–1036 (2014).

    Article  MathSciNet  Google Scholar 

  51. V. P. Varin, “Asymptotic expansion of Crocco solution and the Blasius constant,” Comput. Math. Math. Phys. 58 (4), 517–528 (2018).

    Article  MathSciNet  Google Scholar 

  52. C. M. Bender and S. A. Orszag, Advanced Mathematical Methods for Scientists and Engineers (McGraw-Hill, New York, 1978).

    MATH  Google Scholar 

  53. S. V. Pikulin, “Traveling-wave solutions of the Kolmogorov–Petrovskii–Piskunov equation,” Comput. Math. Math. Phys. 58 (2), 230–237 (2018).

    Article  MathSciNet  Google Scholar 

  54. S. V. Pikulin, “On intermediate asymptotic modes in certain combustion models,” Tavrich. Vestn. Inf. Mat., No. 3 (36), 55–72 (2017).

  55. S. V. Pikulin, “On travelling-wave solutions of a nonlinear parabolic equation,” Vestn. Samar. Gos. Univ. Estestv. Ser., No. 6 (128), 110–116 (2015).

  56. V. V. Golubev, Lectures on the Analytical Theory of Differential Equations (Gostekhizdat, Moscow, 1950) [in Russian].

    MATH  Google Scholar 

  57. E. A. Coddington and N. Levinson, Theory of Ordinary Differential Equations (McGraw-Hill, New York, 1955).

    MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to S. V. Pikulin.

Additional information

Translated by N. Berestova

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Pikulin, S.V. The Thomas–Fermi Problem and Solutions of the Emden–Fowler Equation. Comput. Math. and Math. Phys. 59, 1292–1313 (2019). https://doi.org/10.1134/S096554251908013X

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1134/S096554251908013X

Keywords:

Navigation