Bc. Berndt et al., RAMANUJANS THEORIES OF ELLIPTIC FUNCTIONS TO ALTERNATIVE BASES, Transactions of the American Mathematical Society, 347(11), 1995, pp. 4163-4244
In his famous paper on modular equations and approximations to pi, Ram
anujan offers several series representations for 1/pi, which he claims
are derived from ''corresponding theories'' in which the classical ba
se q is replaced by one of three other bases. The formulas for 1/pi we
re only recently proved by J. M. and P. B. Borwein in 1987, but these
''corresponding theories'' have never been heretofore developed. Howev
er, on six pages of his notebooks, Ramanujan gives approximately 50 re
sults without proofs in these theories. The purpose of this paper is t
o prove all of these claims, and several further results are establish
ed as well.