OAI/GroupTheory/PolycyclicRecognition/Geometry/ComplexNilradical.lean
5 declarations, 0 contain sorry, 0 declared as axioms
The intrinsic meaning of the complex weight kernel
The common kernel consists exactly of the elements with nilpotent adjoint. In particular it is preserved by every Lie automorphism. This identifies the nilpotent factor without making a choice of triangular basis part of its data.
- theorem
OAI.PolycyclicRecognition.ComplexTriangularAdjoint.diagonal_mulline 24 - theorem
OAI.PolycyclicRecognition.ComplexTriangularAdjoint.diagonal_powline 35 - theorem
OAI.PolycyclicRecognition.ComplexTriangularAdjoint.complex_ad_nilpotentline 44Source documentation
Nilpotence of the real adjoint remains nilpotence after scalar extension.
theorem complex_ad_nilpotent (x : L) (hx : IsNilpotent (LieAlgebra.ad ℝ L x)) : IsNilpotent (LieAlgebra.ad ℂ (ℂ ⊗[ℝ] L) (complexificationLieHom L x)) := by … - theorem
OAI.PolycyclicRecognition.ComplexTriangularAdjoint.mem_kernelIdeal_iff_ad_nilpotentline 70Source documentation
The nilpotent kernel is independent of the chosen complex triangular basis.
theorem mem_kernelIdeal_iff_ad_nilpotent (x : L) : x ∈ T.kernelIdeal ↔ IsNilpotent (LieAlgebra.ad ℝ L x) := by … - theorem
OAI.PolycyclicRecognition.ComplexTriangularAdjoint.map_mem_kernelIdealline 88Source documentation
Every Lie automorphism preserves this concrete nilpotent ideal.
theorem map_mem_kernelIdeal (f : L ≃ₗ⁅ℝ⁆ L) {x : L} (hx : x ∈ T.kernelIdeal) : f x ∈ T.kernelIdeal := by …