Module

SigmaEmbeddingSolutions.lean

Nyll.Yamaguchi26AbfaithfulGalois.GroupTheory.SigmaEmbeddingSolutions
2 declarations indexed from sourceView source ↗

Proper finite embedding solutions with faithful abelian Sigma kernels

For each finite quotient, the extension with finite abelian Sigma kernel may be chosen separately. A proper solution is surjective. Its image of the original kernel lies in the Sigma kernel, so the actual residual quotient and its abelianization detect the finite faithful action.

Declarations

ProCGroups.FiniteStepSolvableQuotients.HasFiniteFaithfulAbelianSigmaEmbeddingSolutions

Each finite quotient of each open subgroup admits a suitable finite extension with faithful abelian Sigma kernel and a proper solution.

Source context 3 commands

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

namespace ProCGroups.FiniteStepSolvableQuotients
open ProCGroups.FreeProC.Characterization
universe u
def HasFiniteFaithfulAbelianSigmaEmbeddingSolutions
    (sigma : Set ℕ) (G : Type u)
    [Group G] [TopologicalSpace G] [IsTopologicalGroup G] : Prop
ProCGroups.FiniteStepSolvableQuotients.HasFiniteFaithfulAbelianSigmaEmbeddingSolutions.isSigmaAbFaithful

Proper solutions with faithful abelian Sigma kernels imply the actual Sigma-abelianization-faithfulness condition.

Source context 3 commands

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

namespace ProCGroups.FiniteStepSolvableQuotients
open ProCGroups.FreeProC.Characterization
universe u
theorem HasFiniteFaithfulAbelianSigmaEmbeddingSolutions.isSigmaAbFaithful
    {sigma : Set ℕ} {G : Type u}
    [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
    (hG : HasFiniteFaithfulAbelianSigmaEmbeddingSolutions sigma G) :
    IsSigmaAbFaithful sigma G