OAI/GroupTheory/PolycyclicRecognition/Geometry/BoundaryShadowDescent.lean
1 declarations, 0 contain sorry, 0 declared as axioms
Descending centered ray limits to boundary maps with compact shadows
- theorem
OAI.PolycyclicRecognition.boundary_shadow_of_centered_limitsline 16Source documentation
Continuous fixed-element actions transport normalized ray limits. Asymptotic equality on the actual source fibers then gives a well-defined boundary map and the same common compact shadow.
theorem boundary_shadow_of_centered_limits {G S Q : Type*} [Group G] [Group Q] [TopologicalSpace Q] [T2Space Q] [IsTopologicalGroup Q] (act : G →* Equiv.Perm Q) (hact : ∀ g, Continuous (act g)) (q : G → S) (hq : Function.Surjective q) (F : G → G) (ray : ℕ → G) (K : Set Q) (k : G → Q) (hkK : ∀ x, k x ∈ K) (hk : ∀ x, Tendsto (fun n => act ((F x)⁻¹ * F (x * ray n)) 1) atTop (𝓝 (k x))) (hfiber : ∀ x y, q x = q y → Tendsto (fun n => (act (F (x * ray n)) 1)⁻¹ * act (F (y * ray n)) 1) atTop (𝓝 (1 : Q))) : ∃ B : S → Q, ∀ x, …