Skip to main content
Log in

A new proof of Ramanujan’s modular equation relating R(q) with R(q 5)

  • Published:
The Ramanujan Journal Aims and scope Submit manuscript

Abstract

We give a new proof of Ramanujan’s modular identity relating R(q) with R(q 5), where R(q) is the famous Rogers–Ramanujan continued fraction. Our formulation is stronger than those of preceding authors; in particular, we give for the first time identities for the expressions appearing in the numerator and the denominator of Ramanujan’s identity. A related identity for R(q) that has partition-theoretic connections is also proved.

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.

Similar content being viewed by others

References

  1. Andrews, G.E.: Ramanujan’s “lost” notebook III. The Rogers–Ramanujan continued fraction. Adv. Math. 41, 186–208 (1981)

    Article  MATH  Google Scholar 

  2. Andrews, G.E., Berndt, B.C.: Ramanujan’s Lost Notebook, Part I. Springer, New York (2005)

    Google Scholar 

  3. Andrews, G.E., Paule, P.: MacMahon’s partition analysis XI: Hexagonal plane partitions. Acta Arith. 126(3), 281–294 (2007)

    Article  MATH  MathSciNet  Google Scholar 

  4. Andrews, G.E., Berndt, B.C., Jacobsen, L., Lamphere, R.L.: The Continued Fractions Found in the Unorganized Portions of Ramanujan’s Notebooks. Memoir Amer. Math. Soc., vol. 99, No. 477 (1992)

  5. Berndt, B.C.: Ramanujan’s Notebooks III. Springer, New York (1991)

    MATH  Google Scholar 

  6. Berndt, B.C.: Ramanujan’s Notebooks V. Springer, New York (1998)

    MATH  Google Scholar 

  7. Berndt, B.C., Chan, H.H., Huang, S.-S., Kang, S.-Y., Sohn, J., Son, S.H.: The Rogers–Ramanujan continued fraction. J. Comput. Appl. Math. 105, 9–24 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  8. Berndt, B.C., Huang, S.-S., Sohn, J., Son, S.H.: Some theorems on the Rogers–Ramanujan continued fraction in Ramanujan’s lost notebook. Trans. Am. Math. Soc. 352, 2157–2177 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  9. Bowman, D., McLaughlin, J.: On the divergence of the Rogers–Ramanujan continued fraction on the unit circle. Trans. Am. Math. Soc. 356(8), 3325–3347 (2004)

    Article  MATH  MathSciNet  Google Scholar 

  10. Chan, H.-C., Ebbing, S.: Factorization theorems for the Rogers–Ramanujan continued fraction in the Lost Notebook. Preprint

  11. Gugg, C.: Two modular equations for squares of the Rogers–Ramanujan functions with applications. Ramanujan J. 18(2), 183–207 (2009)

    Article  MathSciNet  Google Scholar 

  12. Gugg, C.: Cubes of the Rogers–Ramanujan functions, analogues, and applications (in preparation)

  13. Hirschhorn, M.D.: On the expansion of Ramanujan’s continued fraction. Ramanujan J. 2(4), 521–527 (1998)

    Article  MATH  MathSciNet  Google Scholar 

  14. Hirschhorn, M.D.: An identity of Ramanujan, and applications. Contemp. Math. 254, 229–234 (2000)

    MathSciNet  Google Scholar 

  15. Hirschhorn, M.D., Hunt, D.C.: A simple proof of the Ramanujan conjecture for powers of 5. J. Reine Angew. Math. 326, 1–17 (1981)

    MATH  MathSciNet  Google Scholar 

  16. Hirschhorn, M.D., Sellers, J.A.: On recent congruence results of Andrews and Paule for broken k-diamond partitions. Bull. Aust. Math. Soc. 75, 121–126 (2007)

    Article  MATH  MathSciNet  Google Scholar 

  17. Kang, S.-Y.: Some theorems on the Rogers–Ramanujan continued fraction and associated theta functions in Ramanujan’s lost notebook. Ramanujan J. 3, 91–111 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  18. Kang, S.-Y.: Ramanujan’s formulas for the explicit evaluation of the Rogers–Ramanujan continued fraction and theta-functions. Acta Arith. 90, 49–68 (1999)

    MATH  MathSciNet  Google Scholar 

  19. Ramanathan, K.G.: On Ramanujan’s continued fraction. Acta Arith. 43, 209–226 (1984)

    MATH  MathSciNet  Google Scholar 

  20. Ramanathan, K.G.: On the Rogers–Ramanujan continued fraction. Proc. Indian Acad. Sci. (Math. Sci.) 93, 67–77 (1984)

    Article  MATH  MathSciNet  Google Scholar 

  21. Ramanathan, K.G.: Ramanujan’s continued fraction. Indian J. Pure Appl. Math. 16, 695–724 (1985)

    MATH  MathSciNet  Google Scholar 

  22. Ramanathan, K.G.: Some applications of Kronecker’s limit formula. J. Indian Math. Soc. 52, 71–89 (1987)

    MATH  MathSciNet  Google Scholar 

  23. Ramanujan, S.: Some properties of p(n), the number of partitions of n. Proc. Camb. Philos. Soc. XIX, 207–210 (1919)

    Google Scholar 

  24. Ramanujan, S.: Notebooks, 2 vols. Tata Instititute of Fundamental Research, Bombay (1957)

    Google Scholar 

  25. Ramanujan, S.: Collected Papers of Srinivasa Ramanujan. Chelsea, New York (1962). Edited with notes by G.H. Hardy, P.V. Aiyar, and B.M. Wilson

    Google Scholar 

  26. Ramanujan, S.: The Lost Notebook and Other Unpublished Papers. Narosa, New Delhi (1988)

    MATH  Google Scholar 

  27. Richmond, B., Szekeres, G.: The Taylor coefficients of certain infinite products. Acta Sci. Math. 40, 347–369 (1978)

    MATH  MathSciNet  Google Scholar 

  28. Rogers, L.J.: Second memoir on the expansion of certain infinite products. Proc. Lond. Math. Soc. 25, 318–343 (1894)

    Article  Google Scholar 

  29. Rogers, L.J.: On a type of modular relation. Proc. Lond. Math. Soc. 19, 387–397 (1921)

    Article  Google Scholar 

  30. Somos, M.: Private communications, October, 2008

  31. Watson, G.N.: Theorems stated by Ramanujan (VII): Theorems on continued fractions. J. Lond. Math. Soc. 4, 39–48 (1929)

    Google Scholar 

  32. Watson, G.N.: Theorems stated by Ramanujan (IX): Two continued fractions. J. Lond. Math. Soc. 4, 231–237 (1929)

    Article  Google Scholar 

  33. Yi, J.: Modular equations for the Rogers–Ramanujan continued fraction and the Dedekind–eta function. Ramanujan J. 5(4), 377–384 (2001)

    Article  MATH  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Chadwick Gugg.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gugg, C. A new proof of Ramanujan’s modular equation relating R(q) with R(q 5). Ramanujan J 20, 163–177 (2009). https://doi.org/10.1007/s11139-009-9180-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11139-009-9180-2

Keywords

Mathematics Subject Classification (2000)

Navigation