Abstract
In this article, we prove the Brent–Salamin algorithm for \(\pi \) using Jacobi’s theta functions and use this approach to derive new analogues of the Brent–Salamin algorithm for elliptic functions to alternative bases.
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References
Berndt, B.C.: Ramanujan’s Notebooks Part II. Springer, New York (1989)
Berndt, B.C.: Ramanujan’s Notebooks Part III. Springer, New York (1991)
Berndt, B.C., Bhargava, S., Garvan, F.G.: Ramanujan’s theories of elliptic functions to alternative bases. Trans. Am. Math. Soc. 347(11), 4163–4244 (1995)
Berndt, B.C., Chan, H.H., Liaw, W.C.: On Ramanujan’s quartic theory of elliptic functions. J. Number Theory 88(1), 129–156 (2001)
Borwein, J.M., Garvan, F.G.: Approximations to \(\pi \) via the Dedekind eta function. Organic mathematics (Burnaby, BC, 1995), pp. 89–115, CMS Conf. Proc., 20, Am. Math. Soc., Providence (1997)
Borwein, J.M., Borwein, P.B.: Pi and the AGM. A Study in Analytic Number Theory and Computational Complexity. Wiley, New York (1987)
Borwein, J.M., Borwein, P.B.: A cubic counterpart of Jacobi’s identity and the AGM. Trans. Am. Math. Soc. 323, 691–701 (1991)
Borwein, J.M., Borwein, P.B., Garvan, F.G.: Some cubic modular identities of Ramanujan. Trans. Am. Math. Soc. 343(1), 35–47 (1994)
Brent, R.P.: Fast multiple-precision evaluation of elementary functions. J. ACM 23, 242–251 (1976)
Chan, H.H.: Ramanujan’s elliptic functions to alternative bases and approximations to \(\pi \). Number Theory for the Millennium, I (Urbana, IL, pp. 197–213. AK Peters, Natick, MA 2000). (2002)
Chan, H.H.: On Ramanujan’s transformation formula for \(_2F_1(1/3,2/3;1;z)\). Math. Proc. Camb. Philos. Soc. 124, 193–204 (1998)
Ramanujan, S.: Modular equations and approximations to \(\pi \). Q. J. Math. (Oxford) 45, 350–372 (1914)
Salamin, E.: Computation of \(\pi \) using arithmetic–geometric mean. Math. Comput. 36, 565–570 (1976)
Siegel, C.L.: A simple proof of \(\eta (-1/\tau ) =\eta (\tau )\sqrt{\tau /i}\). Mathematika 1, 4 (1954)
Acknowledgments
This article is written during my stay at the University of Hong Kong. I would like to thank K. M. Tsang and Y. K. Lau for their warm hospitality. I would also like to thank B. C. Berndt, J. M. Borwein, R. Brent, Y. Tanigawa and K. M. Tsang for their encouragement and discussions during the preparation of this article. Finally, I thank S. Cooper for many of his excellent suggestions which have significantly improved an earlier version of this work.
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Dedicated to Siew Lian, Si Min, Si Ya, and Si En.
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Chan, H.H. Analogues of the Brent–Salamin algorithm for evaluating \(\pi \) . Ramanujan J 38, 75–100 (2015). https://doi.org/10.1007/s11139-014-9560-0
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DOI: https://doi.org/10.1007/s11139-014-9560-0