Title: Number fields and their invariants

Abstract:

Mathematicians often attach `invariants' to the objects they encounter, and a general question is then to which extent these
invariants `characterize' the objects in question.
We will discuss such questions in the context of number fields, and see in the end that the techniques enabling us to construct number fields with `the same absolute abelian Galois group' are also useful in showing that elliptic curves over a number field essentially all have the `same' adelic point group.

Location: KdVI meeting room, Science Park 105-107, F3.20