Module

IdeleClassNorm.lean

Nyll.ClassFieldTheory.AlgebraicNumberTheory.Idele.NormTopology.IdeleClassNorm
4 declarations indexed from sourceView source ↗

The ordinary norm on idele classes

The ordinary idele-class norm preserves the absolute norm and restricts to the norm-one idele-class subgroups.

Declarations

IdeleClassGroup.absoluteNorm_ideleClassNorm

The ordinary idèle-class norm preserves the absolute idèle norm.

Source context 6 commands

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

open scoped NumberField
open NumberField
noncomputable section
namespace IdeleClassGroup
universe u v
variable
    (K : Type u) (L : Type v)
    [Field K] [NumberField K]
    [Field L] [NumberField L]
    [Algebra K L] [FiniteDimensional K L]
theorem absoluteNorm_ideleClassNorm
    (c : IdeleClassGroup L) :
    absoluteNorm (_root_.ideleClassNorm K L c) =
      absoluteNorm c
IdeleClassGroup.ideleClassNorm_mem_normOneSubgroup

The ordinary idele-class norm carries norm-one idele classes to norm-one idele classes.

Source context 6 commands

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

open scoped NumberField
open NumberField
noncomputable section
namespace IdeleClassGroup
universe u v
variable
    (K : Type u) (L : Type v)
    [Field K] [NumberField K]
    [Field L] [NumberField L]
    [Algebra K L] [FiniteDimensional K L]
theorem ideleClassNorm_mem_normOneSubgroup
    (c : IdeleClassGroup L)
    (hc : c ∈ normOneSubgroup (K := L)) :
    _root_.ideleClassNorm K L c ∈
      normOneSubgroup (K := K)
IdeleClassGroup.normOneNorm

The ordinary idele-class norm restricted to the norm-one idele-class groups.

Source context 6 commands

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

open scoped NumberField
open NumberField
noncomputable section
namespace IdeleClassGroup
universe u v
variable
    (K : Type u) (L : Type v)
    [Field K] [NumberField K]
    [Field L] [NumberField L]
    [Algebra K L] [FiniteDimensional K L]
def normOneNorm :
    normOneSubgroup (K := L) →*
      normOneSubgroup (K := K)
IdeleClassGroup.normOneNorm_apply

Coercing the restricted norm-one map recovers the ordinary idèle-class norm.

Source context 6 commands

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

open scoped NumberField
open NumberField
noncomputable section
namespace IdeleClassGroup
universe u v
variable
    (K : Type u) (L : Type v)
    [Field K] [NumberField K]
    [Field L] [NumberField L]
    [Algebra K L] [FiniteDimensional K L]
theorem normOneNorm_apply
    (c : normOneSubgroup (K := L)) :
    (normOneNorm K L c : IdeleClassGroup K) =
      _root_.ideleClassNorm K L c.1