OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanJacobian.lean

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6 declarations, 0 contain sorry, 0 declared as axioms

The Jacobian of actual Cartan conjugation

The nilpotent residual exponential has determinant one. The scalar weight factors multiply to one by the already proved trace balance. Consequently conjugation on the nilpotent Cartan ideal preserves coordinate volume.

  1. theorem OAI.PolycyclicRecognition.det_eq_one_of_sub_one_nilpotent line 22

    Source documentation

    A unipotent real endomorphism has determinant one, including in dimension zero. This uses its actual characteristic polynomial.

    theorem det_eq_one_of_sub_one_nilpotent
        {V : Type*} [AddCommGroup V] [Module ℝ V] [FiniteDimensional ℝ V]
        (F : Module.End ℝ V) (hF : _root_.IsNilpotent (F - 1)) : F.det = 1 := by
    …
  2. theorem OAI.PolycyclicRecognition.det_nilpotent_exp line 34

    Source documentation

    Finite nilpotent exponential has unit determinant.

    theorem det_nilpotent_exp
        {V : Type*} [AddCommGroup V] [Module ℝ V] [FiniteDimensional ℝ V]
        [Module ℚ V] [IsScalarTower ℚ ℝ V]
        (A : Module.End ℝ V) (hA : _root_.IsNilpotent A) :
        LinearMap.det (_root_.IsNilpotent.exp A) = 1 :=
    …
  3. theorem OAI.PolycyclicRecognition.det_cartanIdealResidualAutomorphism line 46

    Source documentation

    The nonsemisimple part of the actual Cartan action has Jacobian one.

    theorem det_cartanIdealResidualAutomorphism (h : H) :
        LinearMap.det (cartanIdealResidualAutomorphism T H h).toLinearEquiv.toLinearMap = 1 := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanIdealResidualAutomorphism

  4. theorem OAI.PolycyclicRecognition.CartanWordModel.det_idealWeightDilation line 57

    Source documentation

    The diagonal scalar action has Jacobian given by the total word weight.

    theorem det_idealWeightDilation (β : M.Bases) (h : H) :
        LinearMap.det (cartanIdealWeightDilation T H h).toLinearEquiv.toLinearMap =
          Real.exp (∑ j, bracketWordExponent (fun i => M.weight i h) (β.val j)) := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanIdealWeightDilation, OAI.PolycyclicRecognition.bracketWordExponent

  5. theorem OAI.PolycyclicRecognition.CartanWordModel.det_idealWeightDilation_eq_one line 78

    Source documentation

    Unimodularity makes all word-basis scalar Jacobians equal to one.

    theorem det_idealWeightDilation_eq_one
        (hunimod : ∀ x : L, LinearMap.trace ℝ L (ad ℝ L x) = 0) (h : H) :
        LinearMap.det (cartanIdealWeightDilation T H h).toLinearEquiv.toLinearMap = 1 := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanIdealWeightDilation

  6. theorem OAI.PolycyclicRecognition.CartanWordModel.det_idealAdjointAutomorphism_eq_one line 98

    Source documentation

    The full actual Cartan action, rather than only its scalar part, has Jacobian one on the nilpotent ideal.

    theorem det_idealAdjointAutomorphism_eq_one
        (hunimod : ∀ x : L, LinearMap.trace ℝ L (ad ℝ L x) = 0) (h : H) :
        LinearMap.det (cartanIdealAdjointAutomorphism T H h).toLinearEquiv.toLinearMap = 1 := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanIdealAdjointAutomorphism