|
|
Given an elliptic curve E defined over a function field F, this function
returns an abelian group A isomorphic to the torsion subgroup of E(F),
together with a map from A to E(F).
TorsionBound(E, n, B) : CrvEll[FldFunG], RngIntElt, RngIntElt -> RngIntElt
Given an elliptic curve over a function field F and an integer n,
this function computes a bound on the size of the torsion subgroup of E(F)
by considering the torsion subgroups of the fibres of E at n different places of F.
When an integer B is given as a third argument then the subgroup of
elements of
order dividing B is bounded, rather than the whole torsion subgroup.
Given an elliptic curve E defined over a function field F,
this function computes a bound for the geometric torsion subgroup of E.
That is, the torsion group of E(K) where K/F is the
smallest extension with algebraically closed constant field.
In cases where a bound cannot be computed then 0 is returned.
[Next][Prev] [Right] [Left] [Up] [Index] [Root]
|
|