|Date||May 01, 2014|
|Dept.||University of Luxembourg|
In this talk, we discuss the cuspidal group of $J_0(pq)$ and the rational torsion points of $J_0(pq)$.
We prove the following statement. If a prime $ell$ does not divide 6pq*gcd(p-1, q-1)*gcd(p-1,q+1)*(q-1,p+1), then the $ell$-primary part of the rational torsion subgroup of $J_0(pq)$ is isomorphic to the $ell$-primary subgroup of the cuspidal group.