Module

RelativeDerivedCriterion.lean

Nyll.Yamaguchi26AbfaithfulGalois.FormalHilbert90.RelativeDerivedCriterion
1 declaration indexed from sourceView source ↗

Relative center-freeness criterion

The earlier all-primes relative criterion, retained in the foundation layer. The current Σ-quotient theorem is Theorem6Dot4RelativeCriterion.lean. The quotient is the actual G/[D,D], with closed commutator subgroup. The orientation hypothesis ranges only over primes with nontrivial primary abelianization of D.

Declarations

Yamaguchi26AbfaithfulGalois.relative_centerfree_and_slim_criterion
Source context 3 commands

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

namespace Yamaguchi26AbfaithfulGalois
open ProCGroups.Abelian ProCGroups.FiniteStepSolvableQuotients
universe u
theorem relative_centerfree_and_slim_criterion
    (G : ProfiniteGrp.{u})
    (D : Subgroup G) [D.Normal]
    (hDclosed : IsClosed (D : Set G)) (hDderived : D ≤ topDerivedTop G 1)
    (hFaithful : ∀ N : OpenNormalSubgroup G,
      D ≤ (N : Subgroup G) →
      Function.Injective
        (quotientConjugationTopologicalAbelianizationMap
          (G := G) (N := (N : Subgroup G))))
    (hOrient : ∀ (ℓ : ℕ) [Fact ℓ.Prime],
      Nontrivial (PrimaryAbelianization ℓ D) →
        ∃ θ : Orientation ℓ G, RelativeFormalHilbert90 D θ) :
    Subgroup.center (RelativeDerivedQuotient D) = ⊥ ∧
      ((∀ (ℓ : ℕ) [Fact ℓ.Prime],
        Nontrivial (PrimaryAbelianization ℓ D) →
          ∃ θ : Orientation ℓ G,
            RelativeFormalHilbert90 D θ ∧ Set.Infinite (Set.range θ)) →
        IsSlim (RelativeDerivedQuotient D))