Module

RealProPStageLocalConditions.lean

Nyll.SawinTotallyRealTowers.RealProPStageLocalConditions
4 declarations indexed from sourceView source ↗

Local conditions of actual finite real p-layers

The global ramification certificates on an admissible finite layer imply the actual chosen-completion conditions used by finite H² localization.

Declarations

ClassFieldTower.Sawin.stageNumberField
Source context 3 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
namespace ClassFieldTower.Sawin
instance stageNumberField (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) : NumberField E.val
ClassFieldTower.Sawin.stageIsGalois
Source context 4 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
namespace ClassFieldTower.Sawin
private local instance stageNumberField (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) : NumberField E.val :=
  NumberField.of_module_finite ℚ E.val
instance stageIsGalois (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) :
    IsGalois ℚ E.val.toIntermediateField
ClassFieldTower.Sawin.finiteRealPExtension_chosenFinitePlaceIsUnramified

The actual chosen completion of an admissible layer is unramified at every finite place outside its allowed support.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
namespace ClassFieldTower.Sawin
private local instance stageNumberField (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) : NumberField E.val :=
  NumberField.of_module_finite ℚ E.val
private local instance stageIsGalois (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) :
    IsGalois ℚ E.val.toIntermediateField := E.val.isGalois
theorem finiteRealPExtension_chosenFinitePlaceIsUnramified
    (p : ℕ) (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T)
    (v : HeightOneSpectrum (𝓞 ℚ)) (hv : v ∉ T) :
    ChosenFinitePlaceIsUnramified (K := ℚ) (L := E.val) v
ClassFieldTower.Sawin.finiteRealPExtension_chosenInfinitePlaceIsUnramified

Every chosen infinite place of an admissible layer is unramified.

Source context 5 commands

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

open scoped NumberField
open NumberField IsDedekindDomain
namespace ClassFieldTower.Sawin
private local instance stageNumberField (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) : NumberField E.val :=
  NumberField.of_module_finite ℚ E.val
private local instance stageIsGalois (p : ℕ)
    (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T) :
    IsGalois ℚ E.val.toIntermediateField := E.val.isGalois
theorem finiteRealPExtension_chosenInfinitePlaceIsUnramified
    (p : ℕ) (T : Set (HeightOneSpectrum (𝓞 ℚ))) (E : FiniteRealPExtension p T)
    (v : InfinitePlace ℚ) :
    (chosenInfinitePlaceAbove (L := E.val) v).IsUnramified ℚ