Ramanujan-type formulae for $$1/\pi$$: a second wind?(English)Zbl 1159.11053

Yui, Noriko (ed.) et al., Modular forms and string duality. Proceedings of a workshop, Banff, Canada, June 3–8, 2006. Providence, RI: American Mathematical Society (AMS); Toronto: The Fields Institute for Research in Mathematical Sciences (ISBN 978-0-8218-4484-7/hbk). Fields Institute Communications 54, 179-188 (2008).
This paper contains a brief survey of the elliptic, modular, hypergeometric, and telescoping methods used to prove formulas for powers of $$1/\pi$$ inspired by Ramanujan’s $$17$$ original examples, one of which is $\sum_{n \geq 0} 2^{-6n}\binom{2n}{n}^3(4n+1)(-1)^n = \frac{2}{\pi}.$ Some directions for future research are indicated.
For the entire collection see [Zbl 1147.11005].

MSC:

 11Y60 Evaluation of number-theoretic constants 11F11 Holomorphic modular forms of integral weight 33C20 Generalized hypergeometric series, $${}_pF_q$$ 33F10 Symbolic computation of special functions (Gosper and Zeilberger algorithms, etc.)
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