[Abstract] F. Garvan; Cubic modular identities of Ramanujan , Trans Amer. Math. Soc, 343 (1994), 35-47.


Abstract: There is a beautiful cubic analogue of Jacobi's fundamental theta function identity: $\theta_3^4 = \theta_4^4 + \theta_2^4$. (see paper for explicit form) In this note we provide an elementary proof of this identity and of a related identity due to Ramanujan.