OAI/GroupTheory/PolycyclicRecognition/Geometry/AlgebraTangentLie.lean
2 declarations, 0 contain sorry, 0 declared as axioms
The Lie algebra of tangent spans
Bilinearity extends the computed commutator identity from curve derivatives to their finite linear span. Thus the derived group controls the derived Lie algebra without a closed-subgroup theorem.
- theorem
OAI.PolycyclicRecognition.algebraGroupTangentSpan_commutatorline 22Source documentation
Commutators of tangent spans lie in the tangent span of the derived group.
theorem algebraGroupTangentSpan_commutator {D : Subgroup Aˣ} {X Y : A} (hX : X ∈ algebraGroupTangentSpan D) (hY : Y ∈ algebraGroupTangentSpan D) : X * Y - Y * X ∈ algebraGroupTangentSpan ⁅D, D⁆ := by … - def
OAI.PolycyclicRecognition.algebraGroupTangentLieline 45Source documentation
The tangent span is a concrete Lie subalgebra of the ambient matrix algebra.
def algebraGroupTangentLie (D : Subgroup Aˣ) : LieSubalgebra ℝ A := …