Does anyone know how to do a 3 descent on a elliptic curve with Z3 torsion?
Is it as simple as silvermans algorithm to do a 2 descent on elliptic curve
with 2 or 4 torsion group? (given in rational points on elliptic curves) I
think one should be able to change his algorithm to work for y^2=x^3+16m^2
with T={oo,(0,+-4m)}. I dont know what would take the place of his mod
squares homomorphism. m=19 with rank 2 would be a good example to
illustrate the algorithm