Module

FiniteQuotientConjugacy.lean

Nyll.ProCGroups.Boundary.FiniteQuotientConjugacy
1 declaration indexed from sourceView source ↗

Detecting conjugacy in finite quotients

In a profinite group, a conjugacy class is compact and hence closed. Thus two elements are conjugate exactly when their images are conjugate in every open-normal quotient.

Declarations

ProCGroups.Boundary.isConj_iff_forall_openNormal_quotient_isConj

Two elements of a profinite group are conjugate if and only if their images are conjugate in every open-normal finite quotient.

Source context 2 commands

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

namespace ProCGroups.Boundary
universe u
theorem isConj_iff_forall_openNormal_quotient_isConj
    {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
    {x y : G} :
    IsConj x y ↔
      ∀ U : OpenNormalSubgroup G,
        IsConj
          (QuotientGroup.mk' (U : Subgroup G) x)
          (QuotientGroup.mk' (U : Subgroup G) y)