Isogenies of prime degree over number fields

Speaker:

Nicolas Billerey

Affiliation:

U Duisburg-Essen

Date:

Wed, 07/04/2010 - 14:15 - 15:15

Location:

MPIM Lecture Hall [2]

Parent event:

Number theory lunch seminar [3]

Let K be a number field and E an elliptic curve defined over K. The so-called exceptional set for (E,K) consisting of prime numbers p such that E has a p-isogeny defined over K is finite iff E does not have CM over K. In this talk, I will state a criterion which allows, in various situations, to explicitly determine the exceptional set when it is finite.