Module

ScalarRestrictionGroupMap.lean

Nyll.SchemeTheory.Normalization.ScalarRestrictionGroupMap
2 declarations indexed from sourceView source ↗

Restriction of scalars on automorphism groups

Bundles algebra automorphisms as group objects and constructs the group morphism that restricts their scalars along an algebra tower.

Declarations

SchemeTheory.galoisGroupObject

The actual Galois automorphism group, retained as its native group object.

Source context 3 commands

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

noncomputable section
namespace SchemeTheory
universe u v w
def galoisGroupObject (K : Type u) (L : Type v)
    [CommRing K] [CommRing L] [Algebra K L] : GrpCat.{v}
SchemeTheory.scalarRestrictionGroupMap

Restricting the original K-linear action to its original A-coefficients.

Source context 3 commands

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

noncomputable section
namespace SchemeTheory
universe u v w
def scalarRestrictionGroupMap
    (A : Type u) (K : Type v) [CommRing A] [Field K] [Algebra A K]
    (C : CommAlgCat.{w} A) [Algebra K C] [IsScalarTower A K C] :
    GrpCat.Hom (galoisGroupObject K C) (commAlgAutomorphismGroup A C) where
  hom' := AlgEquiv.restrictScalarsHom A