Number Theory Seminar

David ZywinaCornell University
Possible indices for the Galois image of elliptic curves over Q

Friday, March 11, 2016 - 2:30pm
Malott 205

For a non-CM elliptic curve $E/Q$, its Galois action on all its torsion points can be expressed in terms of a Galois representation. A famous theorem of Serre says that the image of this representation is as "large as possible" up to finite index. We will study what indices are possible assuming that we are willing to exclude a finite number of possible $j$-invariants from consideration.