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Level 5: The Rogers–Ramanujan Continued Fraction

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Abstract

We prove that

$$\frac{q^{1/5}} {1 + \frac{q} {1+ \frac{q^{2}} {1+ \frac{q^{3}} {1+\cdots }}}} = q^{1/5}\prod _{ j=1}^{\infty }\frac{(1 - q^{5j-4})(1 - q^{5j-1})} {(1 - q^{5j-3})(1 - q^{5j-2})}$$

and develop the rich properties of the infinite product.

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References

  1. G. Almkvist, D. van Straten, W. Zudilin, Generalizations of Clausen’s formula and algebraic transformations of Calabi–Yau differential equations. Proc. Edinb. Math. Soc. 54, 273–295 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  2. G.E. Andrews, The well-poised thread: an organized chronicle of some amazing summations and their implications. Ramanujan J. 1, 7–23 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  3. G.E. Andrews, R. Askey, R. Roy, Special Functions (Cambridge University Press, Cambridge, 1999)

    Book  MATH  Google Scholar 

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

    MATH  Google Scholar 

  5. R. Askey, Math 805 course notes. Hand-written notes reproduced by spirit duplicator (ditto machine), University of Wisconsin, Madison, WI, 1989

    Google Scholar 

  6. W.N. Bailey, A note on two of Ramanujan’s formulae. Q. J. Math. Oxf. Ser. (2) 3, 29–31 (1952)

    Google Scholar 

  7. W.N. Bailey, A further note on two of Ramanujan’s formulae. Q. J. Math. Oxf. Ser. (2) 3, 158–160 (1952)

    Google Scholar 

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

    Book  MATH  Google Scholar 

  9. B.C. Berndt, Number Theory in the Spirit of Ramanujan (American Mathematical Society, Providence, RI, 2006)

    Book  MATH  Google Scholar 

  10. B.C. Berndt, R.A. Rankin, Ramanujan. Letters and Commentary (American Mathematical Society, Providence, RI, 1995)

    Google Scholar 

  11. F. Beukers, Irrationality of π 2, periods of an elliptic curve and Γ 1(5), in Diophantine Approximations and Transcendental Numbers (Luminy, 1982). Progress in Mathematics, vol. 31 (Birkhäuser, Boston, MA, 1983), pp. 47–66

    Google Scholar 

  12. H.H. Chan, Y. Tanigawa, Y. Yang, W. Zudilin, New analogues of Clausen’s identities arising from the theory of modular forms. Adv. Math. 228, 1294–1314 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  13. W. Chu, L. Di Claudio, Classical partition identites and basic hypergeometric series, Dipartimento di Matematica, Università di Lecce, Lecce, 2004

    Google Scholar 

  14. S. Cooper, Theta function identities for level 15, in Ramanujan Rediscovered, ed. by N.D. Baruah, B.C. Berndt, S. Cooper, T. Huber, M. Schlosser. Ramanujan Mathematical Society Lecture Notes Series, vol. 14 (Ramanujan Mathematical Society, Mysore, 2010), pp. 79–86

    Google Scholar 

  15. S. Cooper, M.D. Hirschhorn, Factorizations that involve Ramanujan’s function k(q) = r(q)r 2(q 2). Acta Math. Sin. Engl. Ser. 27, 2301–2308 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  16. S. Cooper, P.C. Toh, Quintic and septic Eisenstein series. Ramanujan J. 19, 163–181 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  17. J.M. Dobbie, A simple proof of some partition formulae of Ramanujan’s. Q. J. Math. Oxf. Ser. (2) 6, 193–196 (1955)

    Google Scholar 

  18. W. Duke, Continued fractions and modular functions. Bull. Am. Math. Soc. (N.S.) 42, 137–162 (2005)

    Google Scholar 

  19. J. Franel, Solution to a question of Laisant. L’intermédiaire des mathématiciens 1, 45–47 (1894)

    Google Scholar 

  20. I. Gessel, Some congruences for Apéry numbers. J. Number Theory 14, 362–368 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  21. G.H. Hardy, Ramanujan. Twelve Lectures on Subjects Suggested by his Life and Work, 3rd edn. (AMS, Providence, RI, 1999)

    Google Scholar 

  22. M.D. Hirschhorn, A simple proof of an identity of Ramanujan. J. Aust. Math. Soc. Ser. A 34, 31–35 (1983)

    Article  MathSciNet  MATH  Google Scholar 

  23. M.D. Hirschhorn, An identity of Ramanujan, and applications, in q-Series from a Contemporary Perspective. Contemporary Mathematics, vol. 254 (American Mathematical Society, Providence, RI, 2000), pp. 229–234

    Google Scholar 

  24. M.D. Hirschhorn, Ramanujan’s “most beautiful identity”. Aust. Math. Soc. Gazette 32, 259–262 (2005)

    MathSciNet  MATH  Google Scholar 

  25. P.J. Larcombe, D.R. French, On the “other” Catalan numbers: a historical formulation re-examined. Congr. Numer. 143, 33–64 (2000)

    MathSciNet  MATH  Google Scholar 

  26. Z.-G. Liu, A theta function identity and the Eisenstein series on Γ 0(5). J. Ramanujan Math. Soc. 22, 283–298 (2007)

    MathSciNet  Google Scholar 

  27. L. Lorentzen, H. Waadeland, Continued Fractions with Applications. Studies in Computational Mathematics, vol. 3 (North-Holland Publishing Co., Amsterdam, 1992)

    Google Scholar 

  28. R.S. Maier, The 192 solutions of the Heun equation. Mathematics of Computation, vol. 76 (2007), pp. 811–843

    Article  MathSciNet  MATH  Google Scholar 

  29. A. Malik, A. Straub, Divisibility properties of sporadic Apéry-like numbers. Res. Number Theory 2, 1–26 (2016). Article 5

    Google Scholar 

  30. S. Ramanujan, Some properties of p(n), the number of partitions of n. Proc. Camb. Philos. Soc. 19, 207–210 (1919). Reprinted in [255, pp. 210–213]

    Google Scholar 

  31. S. Ramanujan, Proof of certain identities in combinatory analysis. Proc. Camb. Philos. Soc. 19, 214–216 (1919) Reprinted in [255, 214–215]

    Google Scholar 

  32. S. Ramanujan, Notebooks, 2 vols. (Tata Institute of Fundamental Research, Bombay, 1957)

    MATH  Google Scholar 

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

    MATH  Google Scholar 

  34. S. Ramanujan, Collected Papers, Third printing (AMS Chelsea, Providence, RI, 2000)

    Google Scholar 

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

    MathSciNet  Google Scholar 

  36. T. Sato (Takeshi Sato), Apéry numbers and Ramanujan’s series for 1∕π. Abstract of a talk presented the Annual Meeting of the Mathematical Society of Japan, 28–31 March, 2002

    Google Scholar 

  37. A. Selberg, Über einige arithmetische Identitäten. Avhandlinger utgitt av Det Norske Videnskaps-Akademi i Oslo I. Mat.-Naturv. Klasse, no. 8 (1936), pp. 1–23. Reprinted in Collected Papers, vol. 1 (Springer, Berlin, 1989)

    Google Scholar 

  38. N.J.A. Sloane, The on-line encyclopedia of integer sequences. http://www.research.att.com/njas/sequences/ (webpage accessed: February 2017)

  39. E.T. Whittaker, G.N. Watson, A Course of Modern Analysis, 4th edn. (Cambridge University Press, Cambridge, 1927)

    MATH  Google Scholar 

  40. D. Zagier, Integral solutions of Apéry-like recurrence equations, in Groups and Symmetries. CRM Proceedings of Lecture Notes, vol. 47 (American Mathematical Society, Providence, RI, 2009), pp. 349–366

    Google Scholar 

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Cooper, S. (2017). Level 5: The Rogers–Ramanujan Continued Fraction. In: Ramanujan's Theta Functions. Springer, Cham. https://doi.org/10.1007/978-3-319-56172-1_6

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