Module

Theorem6Dot2IntegralInvariants.lean

Nyll.Yamaguchi26AbfaithfulGalois.Theorem6Dot2IntegralInvariants
1 declaration indexed from sourceView source ↗

Lemma 6.2: integral invariants

Source: Yamaguchi, arXiv:2610.05634v1, Lemma 6.2. The stronger torsion-freeness and fixed-inclusion theorem is retained in FormalHilbert90/OrientedInvariants.lean.

Declarations

Yamaguchi26AbfaithfulGalois.integral_invariants_6_2

Under formal Hilbert 90 the primary abelianization of a closed normal subgroup of the closed derived group has no global invariants. An infinite orientation also excludes invariants under every open subgroup.

Source context 3 commands

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

namespace Yamaguchi26AbfaithfulGalois
open ProCGroups.Abelian ProCGroups.FiniteStepSolvableQuotients
universe u
theorem integral_invariants_6_2
    {ℓ : ℕ} [Fact ℓ.Prime] (G : ProfiniteGrp.{u})
    (D : Subgroup G) [D.Normal] (hDclosed : IsClosed (D : Set G))
    (hDderived : D ≤ topDerivedTop G 1)
    (θ : Orientation ℓ G) (hθ : FormalHilbert90 θ) :
    primaryFixedSubgroup ℓ D hDclosed (⊤ : Subgroup G) = ⊥ ∧
      (Set.Infinite (Set.range θ) → ∀ H : OpenSubgroup G,
        primaryFixedSubgroup ℓ D hDclosed (H : Subgroup G) = ⊥)