abelian number field
Definition 1.
An abelian number field is a number field such that is an abelian extension
, i.e. is Galois and is an abelian group
.
The abelian number fields are classified by the Kronecker-Weber Theorem.
Definition 2.
A cyclic number field is an (abelian) number field such that is a Galois extension and is a finite cyclic group
(therefore abelian).