L-function
L-function
For every elliptic curve E over ℚ, the rank of the Mordell–Weil group E(ℚ) equals the order of vanishing of the Hasse–Weil L-function L(E,s) at s = 1. Finiteness of Sha is part of the expected picture.
L-function —lemma→ BSD
L-function —implies→ Rank = ord L(E,1)