Binary forms with covariant points close to the real axis
Binary forms with covariant points close to the real axis
For a real binary form $F(X, Z)$, Stoll and Cremona have defined a reduction theory using the action of the modular group $SL_2(\mathbb{Z})$, and associated to each binary form a covariant point $z(F)$ located in the upper half plane. When the point $z(F)$ is close to the real axis, then …