Module

Theorem6Dot4RelativeCriterion.lean

Nyll.Yamaguchi26AbfaithfulGalois.Theorem6Dot4RelativeCriterion
1 declaration indexed from sourceView source ↗

Theorem 6.4: center-freeness and slimness of G/R_Σ(D)

Source: Yamaguchi, arXiv:2610.05634v1, Theorem 6.4. The previous criterion for G/[D,D], requiring only relative Hilbert 90, is retained in FormalHilbert90/RelativeDerivedCriterion.lean.

Declarations

Yamaguchi26AbfaithfulGalois.relative_centerfree_and_slim_criterion_6_4
Source context 3 commands

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

namespace Yamaguchi26AbfaithfulGalois
open ProCGroups ProCGroups.Abelian ProCGroups.FiniteStepSolvableQuotients
universe u
theorem relative_centerfree_and_slim_criterion_6_4
    (sigma : Set ℕ) (G : ProfiniteGrp.{u}) (hG : IsSigmaAbFaithful sigma G)
    (D : ClosedSubgroup G) [(D : Subgroup G).Normal]
    (hDderived : (D : Subgroup G) ≤ topDerivedTop G 1)
    (hOrient : ∀ (p : ℕ) [Fact p.Prime], p ∈ sigma →
      Nontrivial (PrimaryAbelianization p (D : Subgroup G)) →
        ∃ θ : Orientation p G, FormalHilbert90 θ) :
    Subgroup.center (G ⧸ sigmaResidualKernel sigma D) = ⊥ ∧
      ((∀ (p : ℕ) [Fact p.Prime], p ∈ sigma →
        Nontrivial (PrimaryAbelianization p (D : Subgroup G)) →
          ∃ θ : Orientation p G, FormalHilbert90 θ ∧ Set.Infinite (Set.range θ)) →
            IsSlim (G ⧸ sigmaResidualKernel sigma D))