Module

GlobalMaximalAbelianRestriction.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Global.GlobalMaximalAbelianRestriction
3 declarations indexed from sourceView source ↗

Restriction to the actual maximal abelian subextension

Declarations

ClassFieldTower.Martinet.Shafarevich.globalMaximalAbelianRestriction

Restrict the standard absolute Galois group to the maximal abelian subextension of the fixed separable closure.

Source context 3 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
variable (F : Type) [Field F]
def globalMaximalAbelianRestriction :
    Field.absoluteGaloisGroup F →ₜ* Gal(_root_.maximalAbelianExtension F / F)
ClassFieldTower.Martinet.Shafarevich.globalMaximalAbelianRestriction_apply
Source context 3 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
variable (F : Type) [Field F]
theorem globalMaximalAbelianRestriction_apply (sigma : Field.absoluteGaloisGroup F) :
    globalMaximalAbelianRestriction F sigma =
      AlgEquiv.restrictNormalHom (_root_.maximalAbelianExtension F)
        (RamificationTheory.Field.absoluteGaloisGroup.separableClosureContinuousMulEquiv F sigma)
ClassFieldTower.Martinet.Shafarevich.globalMaximalAbelianRestriction_surjective

Absolute automorphisms surject onto the maximal abelian Galois group.

Source context 3 commands

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

noncomputable section
namespace ClassFieldTower.Martinet.Shafarevich
variable (F : Type) [Field F]
theorem globalMaximalAbelianRestriction_surjective :
    Function.Surjective (globalMaximalAbelianRestriction F)