OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanJordanDecomposition.lean
3 declarations, 0 contain sorry, 0 declared as axioms
Identifying the Cartan weight operator as the semisimple part
The polynomial Jordan decomposition shows that the weight operator preserves every subspace preserved by the original adjoint operator. This will keep the original triangular flag when the weight operator is subtracted.
- theorem
OAI.PolycyclicRecognition.cartanWeightOperator_jordanline 23 - theorem
OAI.PolycyclicRecognition.cartanWeightOperator_upperline 46 - theorem
OAI.PolycyclicRecognition.heightReducedAdjoint_nilpotentline 59Source documentation
Removing the semisimple height action leaves a strictly triangular operator in the original adjoint flag.
theorem heightReducedAdjoint_nilpotent (x : L) : IsNilpotent (ad ℝ L x - (heightSemisimpleAction T H x).toLinearMap) := by …