OAI/GroupTheory/PolycyclicRecognition/Geometry/ExponentialEmbedding.lean
3 declarations, 0 contain sorry, 0 declared as axioms
Closed embeddings from compatible global exponential charts
An injective map of finite-dimensional real Lie algebras is closed in linear coordinates. Compatible global exponential charts transfer that property to the integrated subgroup map. This supplies the properness required for fixed-slice packing, without adding a closed-subgroup hypothesis.
- theorem
OAI.PolycyclicRecognition.isClosedEmbedding_of_compatible_chartsline 27Source documentation
Global exponential charts turn an injective linear inclusion into a closed topological embedding. No group-theoretic splitting is required.
theorem isClosedEmbedding_of_compatible_charts (cN : V ≃ₜ N) (cG : U ≃ₜ G) (j : V →ₗ[ℝ] U) (hj : Function.Injective j) (f : N → G) (hf : ∀ x, f (cN x) = cG (j x)) : Topology.IsClosedEmbedding f := by … - theorem
OAI.PolycyclicRecognition.isClosedEmbedding_of_exponential_compatibilityline 40Source documentation
The same conclusion with separately named intrinsic exponentials.
theorem isClosedEmbedding_of_exponential_compatibility (cN : V ≃ₜ N) (cG : U ≃ₜ G) (ExpN : V → N) (ExpG : U → G) (hN : ∀ x, cN x = ExpN x) (hG : ∀ x, cG x = ExpG x) (j : V →ₗ[ℝ] U) (hj : Function.Injective j) (f : N → G) (hf : ∀ x, f (ExpN x) = ExpG (j x)) : Topology.IsClosedEmbedding f := by … - theorem
OAI.PolycyclicRecognition.isCompact_preimage_of_exponential_compatibilityline 52Source documentation
In particular compact ambient regions have compact sets of subgroup parameters. This will bound fixed-radius ball multiplicities.
theorem isCompact_preimage_of_exponential_compatibility (cN : V ≃ₜ N) (cG : U ≃ₜ G) (ExpN : V → N) (ExpG : U → G) (hN : ∀ x, cN x = ExpN x) (hG : ∀ x, cG x = ExpG x) (j : V →ₗ[ℝ] U) (hj : Function.Injective j) (f : N → G) (hf : ∀ x, f (ExpN x) = ExpG (j x)) {K : Set G} (hK : IsCompact K) : IsCompact (f ⁻¹' K) := …