OAI/GroupTheory/PolycyclicRecognition/Algebra/TupleLiftProjection.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Projection of thickened endpoint tuples into increment coordinates
Bounding the auxiliary coordinates costs at most their product volume. The subsequent change from total nilpotent coordinates to increments is Haar preserving, including for noncommutative nilpotent groups.
- def
OAI.PolycyclicRecognition.tupleIncrementRegionline 23 - theorem
OAI.PolycyclicRecognition.tuple_lift_projection_volumeline 28Source documentation
The projection estimate needed before applying the polynomial endpoint map to the joint increment set.
theorem tuple_lift_projection_volume (μ : Measure N) [SigmaFinite μ] [μ.IsMulLeftInvariant] (ν : Measure D) [SFinite ν] (h : ℕ) {K : Set ((Fin h → N) × D)} (hK : IsCompact K) {Q : Set D} (hQ : ∀ z ∈ K, z.2 ∈ Q) : MeasurableSet (tupleIncrementRegion h K) ∧ ((Measure.pi fun _ : Fin h => μ).prod ν) K ≤ (Measure.pi fun _ : Fin h => μ) (tupleIncrementRegion h K) * ν Q := by …