OAI/GroupTheory/PolycyclicRecognition/Geometry/CoordinateLieBrackets.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

The actual Lie law in a chosen basis

Transport the original bracket to Euclidean coordinates, retaining its exact word identities. A bound on basis structure constants gives a bound in the finite-dimensional parameter space used for normalized-law compactness.

  1. def OAI.PolycyclicRecognition.basisBracketLinear line 23

    Source documentation

    Coordinate transport of the bracket, initially as a bilinear map.

    def basisBracketLinear : (Fin n → ℝ) →ₗ[ℝ] (Fin n → ℝ) →ₗ[ℝ] (Fin n → ℝ) where
    …
  2. def OAI.PolycyclicRecognition.basisBracket line 45

    Source documentation

    The same coordinate bracket in the normed space of continuous bilinear maps.

    def basisBracket : (Fin n → ℝ) →L[ℝ] (Fin n → ℝ) →L[ℝ] (Fin n → ℝ) :=
    …
  3. theorem OAI.PolycyclicRecognition.basisBracket_apply line 50
  4. theorem OAI.PolycyclicRecognition.isLieBracket_basisBracket line 55

    Source documentation

    The transported operation is a genuine Lie bracket, not only a bounded bilinear operation.

    theorem isLieBracket_basisBracket : IsLieBracket (basisBracket b) := by
    …

    Mentions: OAI.PolycyclicRecognition.IsLieBracket, OAI.PolycyclicRecognition.basisBracket

  5. theorem OAI.PolycyclicRecognition.evalBilinearWord_basisBracket line 64

    Source documentation

    Word evaluation commutes exactly with the coordinate transport.

    theorem evalBilinearWord_basisBracket {I : Type*} (X : I → L) (w : FreeMagma I) :
        evalBilinearWord (basisBracket b) (fun i => b.equivFun (X i)) w =
          b.equivFun (evalBracketWord X w) := by
    …

    Mentions: OAI.PolycyclicRecognition.evalBilinearWord, OAI.PolycyclicRecognition.basisBracket, OAI.PolycyclicRecognition.evalBracketWord

  6. theorem OAI.PolycyclicRecognition.norm_basisBracket_le line 76

    Source documentation

    The structure-constant estimate controls the norm of the actual law in the fixed coordinate parameter space.

    theorem norm_basisBracket_le {C : ℝ} (hC : 0 ≤ C)
        (hb : ∀ i j k, |b.repr ⁅b i, b j⁆ k| ≤ C) :
        ‖basisBracket b‖ ≤ (n : ℝ) ^ 2 * C := by
    …

    Mentions: OAI.PolycyclicRecognition.basisBracket