OAI/GroupTheory/PolycyclicRecognition/Algebra/NilpotentGenerators.lean
4 declarations, 0 contain sorry, 0 declared as axioms
Lifting generators from the nilpotent abelianization
For the Cartan model, homogeneous lifts of a basis modulo the derived algebra generate the whole nilpotent ideal. The proof pushes the error down its actual lower central series; no generation hypothesis is substituted for this step.
- theorem
OAI.PolycyclicRecognition.span_sup_lowerCentralSeries_one_of_lieSpanline 18Source documentation
Lie generation implies linear spanning modulo brackets.
theorem span_sup_lowerCentralSeries_one_of_lieSpan (S : Set L) (hS : LieSubalgebra.lieSpan ℝ L S = ⊤) : Submodule.span ℝ S ⊔ (LieModule.lowerCentralSeries ℝ L L 1).toSubmodule = ⊤ := by … - theorem
OAI.PolycyclicRecognition.lieSubalgebra_sup_lowerCentralSeriesline 38 - theorem
OAI.PolycyclicRecognition.lieSubalgebra_eq_top_of_sup_lowerCentralSeries_oneline 77Source documentation
Lifts spanning the abelianization generate a nilpotent Lie algebra.
theorem lieSubalgebra_eq_top_of_sup_lowerCentralSeries_one [LieRing.IsNilpotent L] (U : LieSubalgebra ℝ L) (hU : U.toSubmodule ⊔ (LieModule.lowerCentralSeries ℝ L L 1).toSubmodule = ⊤) : U = ⊤ := by … - theorem
OAI.PolycyclicRecognition.exists_bracketWord_basis_of_abelianizationline 87Source documentation
The resulting generating family has a basis of evaluated bracket words.
theorem exists_bracketWord_basis_of_abelianization [LieRing.IsNilpotent L] [FiniteDimensional ℝ L] {I : Type*} (X : I → L) (hX : Submodule.span ℝ (Set.range X) ⊔ (LieModule.lowerCentralSeries ℝ L L 1).toSubmodule = ⊤) : ∃ b : Module.Basis (Fin (Module.finrank ℝ L)) ℝ L, ∀ k, ∃ w : FreeMagma I, evalBracketWord X w = b k := by …