Circular summation of theta functions in Ramanujan’s Lost Notebook

In this paper, we prove Ramanujan’s circular summation formulas previously studied by S.S. Rangachari, S.H. Son, K. Ono, S. Ahlgren and K.S. Chua using properties of elliptic and theta functions. We also derive identities similar to Ramanujan’s summation formula and connect these identities to Jacobi’s and Dixon’s elliptic functions. At the end of the paper, we discuss the connection of our results with the recent thesis of E. Conrad.  2005 Elsevier Inc. All rights reserved