Module

SmallHilbertClassFieldExists.lean

Nyll.ClassFieldTheory.Theorems.FrobeniusAndHilbertClassFields.SmallHilbertClassFieldExists
1 declaration indexed from sourceView source ↗

Existence of the small Hilbert class field

The small Hilbert class field is characterized as an everywhere-unramified finite abelian extension containing every other such extension. In particular, real places are required to remain unramified.

Declarations

ClassFieldTheory.exists_smallHilbertClassField

A maximal everywhere-unramified finite abelian extension exists.

Source context 2 commands

Surrounding namespaces, section variables, and local commands at this declaration.

open scoped NumberField
namespace ClassFieldTheory
theorem exists_smallHilbertClassField
    (K : Type) [Field K] [NumberField K] :
    ∃ E : FiniteAbelianExtension K, IsSmallHilbertClassField E