Module

TopologicalInertia.lean

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

Topologically cyclic inertia and cyclotomic inversion

This file upgrades the elementwise abelian consequence of cyclotomic inversion to a statement about an entire topologically cyclic inertia group. The generator is killed by inversion and oddness, and continuity then kills the whole restriction.

Declarations

ProCGroups.Boundary.restriction_eq_one_of_topological_generator_isConj_inv_of_coprime_two

A continuous map to an abelian Hausdorff group is trivial on a topologically cyclic inertia group when the image of a topological generator has order prime to two and its ambient image is conjugate to its inverse.

Source context 2 commands

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

namespace ProCGroups.Boundary
universe u v w
theorem restriction_eq_one_of_topological_generator_isConj_inv_of_coprime_two
    {I : Type u} {G : Type v} {A : Type w}
    [Group I] [TopologicalSpace I] [IsTopologicalGroup I]
    [Group G] [TopologicalSpace G]
    [CommGroup A] [TopologicalSpace A] [T2Space A]
    (inertiaMap : I →ₜ* G) (q : G →ₜ* A) {gamma : I}
    (hGenerates :
      Generation.TopologicallyGenerates (G := I) ({gamma} : Set I))
    (hConj : IsConj (inertiaMap gamma) (inertiaMap gamma)⁻¹)
    (hCoprime : Nat.Coprime (orderOf (q (inertiaMap gamma))) 2) :
    q.comp inertiaMap = 1