OAI/GroupTheory/PolycyclicRecognition/Analysis/CompactLiftQuotient.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Compact lifts and the topology of the actual quotient orbit
- theorem
OAI.PolycyclicRecognition.isQuotientMap_of_compact_liftsline 16Source documentation
A continuous surjection with compact lifts of compact sets is a quotient map into a Hausdorff compactly generated space.
theorem isQuotientMap_of_compact_lifts {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] [T2Space Y] [CompactlyGeneratedSpace Y] (f : X → Y) (hf : Continuous f) (hsurj : Function.Surjective f) (hlift : ∀ K : Set Y, IsCompact K → ∃ C : Set X, IsCompact C ∧ K ⊆ f '' C) : IsQuotientMap f := by … - theorem
OAI.PolycyclicRecognition.CartanFactorModel.orbitMap_isQuotientMapline 51Source documentation
The actual orbit map is a quotient map. Its topology follows from compact Cartan lifts and a continuous section of the nilpotent projection.
theorem orbitMap_isQuotientMap (π : F.N.carrier →* Q) (hπ : Continuous π) (s : Q → F.N.carrier) (hs : Continuous s) (hsection : Function.RightInverse s π) (α : F.D.carrier →* MulAut Q) (act : G →* Equiv.Perm Q) (hact : ∀ u d q, act (F.inclusionN u * F.inclusionD d) q = π u * α d q) : IsQuotientMap (fun g => act g 1) := by …