Module

ActualFiniteWildRestriction.lean

Nyll.EtaleFundamentalGroups.Inertia.ActualFiniteWildRestriction
3 declarations indexed from sourceView source ↗

Surjective actual finite wild restrictions

The induced map uses the literal actual inertia restriction. Its image equality was proved from the original data, so preservation and surjectivity are conclusions, with no comparison premise supplied by a caller.

Declarations

EtaleFundamentalGroups.Inertia.actualFiniteWildTowerRestriction

The actual induced restriction on the SAME intrinsic finite wild groups.

Source context 5 commands

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

noncomputable section
namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [IsDiscreteValuationRing A]
  [Field K] [Field L] [Algebra A K] [IsFractionRing A K]
  [Algebra K L] [Algebra A L] [IsScalarTower A K L] [IsGalois K L]
  (Q : Ideal (normalizationCommAlgCat A L).carrier) [Q.IsMaximal]
  (E F : FiniteGaloisIntermediateField K L) (hEF : E ≤ F)
def actualFiniteWildTowerRestriction :
    GrpCat.Hom (actualFiniteWildGroup A K L Q F) (actualFiniteWildGroup A K L Q E) where
  hom' := subgroupRestrictionOfImage
    (actualFiniteInertiaTowerRestriction A K L Q E F hEF).hom'
    (actualFiniteWildSubgroup A K L Q F) (actualFiniteWildSubgroup A K L Q E)
    (actualFiniteWildSubgroup_map A K L Q E F hEF)
EtaleFundamentalGroups.Inertia.actualFiniteWildTowerRestriction_val

On its underlying inertia element this is precisely the actual rho.

Source context 5 commands

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

noncomputable section
namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [IsDiscreteValuationRing A]
  [Field K] [Field L] [Algebra A K] [IsFractionRing A K]
  [Algebra K L] [Algebra A L] [IsScalarTower A K L] [IsGalois K L]
  (Q : Ideal (normalizationCommAlgCat A L).carrier) [Q.IsMaximal]
  (E F : FiniteGaloisIntermediateField K L) (hEF : E ≤ F)
theorem actualFiniteWildTowerRestriction_val
    (sigma : (actualFiniteWildGroup A K L Q F).carrier) :
    ((actualFiniteWildTowerRestriction A K L Q E F hEF).hom'.toFun sigma).val =
      (actualFiniteInertiaTowerRestriction A K L Q E F hEF).hom'.toFun sigma.val
EtaleFundamentalGroups.Inertia.actualFiniteWildTowerRestriction_surjective

The same induced actual wild restriction is surjective.

Source context 5 commands

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

noncomputable section
namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing A] [IsDomain A] [IsDiscreteValuationRing A]
  [Field K] [Field L] [Algebra A K] [IsFractionRing A K]
  [Algebra K L] [Algebra A L] [IsScalarTower A K L] [IsGalois K L]
  (Q : Ideal (normalizationCommAlgCat A L).carrier) [Q.IsMaximal]
  (E F : FiniteGaloisIntermediateField K L) (hEF : E ≤ F)
theorem actualFiniteWildTowerRestriction_surjective :
    Function.Surjective (actualFiniteWildTowerRestriction A K L Q E F hEF).hom'.toFun