Modular elliptic curve

A modular elliptic curve is an elliptic curve E that admits a parametrisation X₀(N) → E by a modular curve. This is not the same as a modular curve that happens to be an elliptic curve, and which could be called an elliptic modular curve. The modularity theorem, formerly known as the Taniyama–Shimura conjecture asserts that every elliptic curve defined over the rational numbers is modular.

Equivalent formulations

Equivalent to the above formulation of modularity is that the L-series of E agrees with the L-series of a normalized eigenform.