Module

RelativeFixedPoints.lean

Nyll.Yamaguchi26AbfaithfulGalois.FormalHilbert90.RelativeFixedPoints
4 declarations indexed from sourceView source ↗

Relative derived quotients and fixed primary classes

Centralizing classes in relative derived quotients yield fixed primary abelianization classes. Vanishing of these fixed classes forces the centralizing quotient class to be trivial.

Declarations

Yamaguchi26AbfaithfulGalois.relativeDerived_mem_iff
Source context 4 commands

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

open scoped commutatorElement
namespace Yamaguchi26AbfaithfulGalois
open ProCGroups.FiniteStepSolvableQuotients ProCGroups.Abelian ProCGroups.ProC
universe u
theorem relativeDerived_mem_iff
    {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    (D : Subgroup G) (hD : IsClosed (D : Set G)) (d : D) :
    (d : G) ∈ relativeDerived D ↔ TopologicalAbelianization.mk D d = 1
Yamaguchi26AbfaithfulGalois.relativeDerived_quotient_mem_openNormal_of_centralizes
Source context 4 commands

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

open scoped commutatorElement
namespace Yamaguchi26AbfaithfulGalois
open ProCGroups.FiniteStepSolvableQuotients ProCGroups.Abelian ProCGroups.ProC
universe u
theorem relativeDerived_quotient_mem_openNormal_of_centralizes
    {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    (D : Subgroup G) [D.Normal]
    (N : OpenNormalSubgroup G) (hDN : D ≤ (N : Subgroup G))
    (hN : Function.Injective
      (quotientConjugationTopologicalAbelianizationMap (G := G) (N := (N : Subgroup G))))
    (x : G)
    (hx : QuotientGroup.mk' (relativeDerived D) x ∈
      Subgroup.centralizer (((N : Subgroup G).map
        (QuotientGroup.mk' (relativeDerived D))) : Set (RelativeDerivedQuotient D))) :
    x ∈ (N : Subgroup G)
Yamaguchi26AbfaithfulGalois.primaryAbelianization_mk_mem_fixed_of_quotient_centralizes
Source context 4 commands

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

open scoped commutatorElement
namespace Yamaguchi26AbfaithfulGalois
open ProCGroups.FiniteStepSolvableQuotients ProCGroups.Abelian ProCGroups.ProC
universe u
theorem primaryAbelianization_mk_mem_fixed_of_quotient_centralizes
    {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G] [CompactSpace G]
    (D : Subgroup G) [D.Normal] (hD : IsClosed (D : Set G))
    (H : Subgroup G) (d : D)
    (hd : QuotientGroup.mk' (relativeDerived D) (d : G) ∈
      Subgroup.centralizer (H.map (QuotientGroup.mk' (relativeDerived D)) :
        Set (RelativeDerivedQuotient D)))
    (p : ℕ) [Fact p.Prime] :
    QuotientGroup.mk' (proCResidualCore (ProCGroups.FiniteGroupClass.pGroup p)
      (TopologicalAbelianization D)) (TopologicalAbelianization.mk D d) ∈
      primaryFixedSubgroup p D hD H
Yamaguchi26AbfaithfulGalois.relativeDerived_quotient_eq_one_of_primaryFixed_eq_bot
Source context 4 commands

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

open scoped commutatorElement
namespace Yamaguchi26AbfaithfulGalois
open ProCGroups.FiniteStepSolvableQuotients ProCGroups.Abelian ProCGroups.ProC
universe u
theorem relativeDerived_quotient_eq_one_of_primaryFixed_eq_bot
    {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
    (D : Subgroup G) [D.Normal] (hD : IsClosed (D : Set G))
    (H : Subgroup G)
    (hfixed : ∀ (p : ℕ) [Fact p.Prime],
      Nontrivial (PrimaryAbelianization p D) → primaryFixedSubgroup p D hD H = ⊥)
    (d : D)
    (hd : QuotientGroup.mk' (relativeDerived D) (d : G) ∈
      Subgroup.centralizer (H.map (QuotientGroup.mk' (relativeDerived D)) :
        Set (RelativeDerivedQuotient D))) :
    QuotientGroup.mk' (relativeDerived D) (d : G) = 1