| Résume | In this talk, I'll describe a construction of a family of cohomology classes in the product of the Galois representations attached to two weight 2 modular forms over cyclotomic fields, generalizing constructions of Beilinson, Flach, and Bertolini-Darmon-Rotger. These classes form an ``Euler system'', which can be used to bound the size of Selmer groups. I will also discuss applications of this construction to the Iwasawa theory of a single modular form over an imaginary quadratic field. |
