Birch and Swinnerton-Dyer Conjecture
Relates rational points on elliptic curves to the behavior of their L-functions at s = 1.
The Birch and Swinnerton-Dyer conjecture predicts that the algebraic rank of an elliptic curve E over the rationals -- the number of independent rational points of infinite order -- equals the analytic rank, the order of vanishing of its Hasse-Weil L-function L(E,s) at s = 1. A refined version gives a precise formula for the leading Taylor coefficient involving the Tate-Shafarevich group, the regulator, real periods, and Tamagawa numbers. The conjecture emerged from extensive numerical computation on the Cambridge EDSAC-2 in the early 1960s. Major partial results include the Coates-Wiles theorem (1977) for CM curves, the Gross-Zagier formula (1986) connecting Heegner points to L-function derivatives, and Kolyvagin's Euler system method (1989) settling the rank 0 and 1 cases for modular elliptic curves.
Formula
The algebraic rank of the group of rational points on E equals the analytic rank (order of vanishing of the L-function at s = 1).
The Hasse–Weil L-function of E encodes local point counts a_p = p + 1 − #E(𝔽_p) at each prime.
The refined conjecture predicts the leading Taylor coefficient in terms of the Sha group, regulator, period, and Tamagawa numbers.
Summary
The Birch and Swinnerton-Dyer conjecture predicts that the algebraic rank of an elliptic curve E over the rationals -- the number of independent rational points of infinite order -- equals the analytic rank, the order of vanishing of its Hasse-Weil L-function L(E,s) at s = 1. A refined version gives a precise formula for the leading Taylor coefficient involving the Tate-Shafarevich group, the regulator, real periods, and Tamagawa numbers. The conjecture emerged from extensive numerical computation on the Cambridge EDSAC-2 in the early 1960s. Major partial results include the Coates-Wiles theorem (1977) for CM curves, the Gross-Zagier formula (1986) connecting Heegner points to L-function derivatives, and Kolyvagin's Euler system method (1989) settling the rank 0 and 1 cases for modular elliptic curves.

