The Gross-Zagier formula relates the first derivative at the central point
of a Rankin L-series to the canonical
height of a Heegner point. For a normalized
weight-2 modular newform
, a suitable character
of the class group of an
imaginary quadratic field, and the corresponding
Heegner point
,
it has the schematic form
where
is an explicit positive factor depending on the normalizations and
is the canonical height.
Consequently, a nonzero derivative implies that
has infinite order. Together with Kolyvagin's work, the
Gross-Zagier formula shows that a modular elliptic
curve of analytic rank one has Mordell-Weil rank one and a finite Tate-Shafarevich
group (Gross and Zagier 1986, Kolyvagin 1989).