OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanJacobian.lean
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.
- theorem
OAI.PolycyclicRecognition.det_eq_one_of_sub_one_nilpotentline 22Source 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 … - theorem
OAI.PolycyclicRecognition.det_nilpotent_expline 34Source 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 := … - theorem
OAI.PolycyclicRecognition.det_cartanIdealResidualAutomorphismline 46Source 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
- theorem
OAI.PolycyclicRecognition.CartanWordModel.det_idealWeightDilationline 57Source 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
- theorem
OAI.PolycyclicRecognition.CartanWordModel.det_idealWeightDilation_eq_oneline 78Source 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
- theorem
OAI.PolycyclicRecognition.CartanWordModel.det_idealAdjointAutomorphism_eq_oneline 98Source 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