Let E be an elliptic curve with equation $y^2=x^3+Ax+B$.
The projection onto the $x$-coordinate is a Galois morphism of degree $2$.
But what about the projection onto the $y$-coordinate? Is it Galois of degree 3? Where does one study this map?
Let E be an elliptic curve with equation $y^2=x^3+Ax+B$.
The projection onto the $x$-coordinate is a Galois morphism of degree $2$.
But what about the projection onto the $y$-coordinate? Is it Galois of degree 3? Where does one study this map?