OAI/GroupTheory/PolycyclicRecognition/Geometry/DiscreteNilpotentLieGroup.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Discrete subgroups of simply connected nilpotent Lie groups
Nilpotence makes every adjoint operator have only the zero generalized weight. A simultaneous triangular basis therefore has zero height, and the discrete height-kernel theorem applies to the whole group.
- theorem
OAI.PolycyclicRecognition.nonempty_triangularAdjoint_of_nilpotentline 21Source documentation
Engel nilpotence supplies the split adjoint basis needed by the concrete height-kernel argument.
theorem nonempty_triangularAdjoint_of_nilpotent (L : Type*) [LieRing L] [LieAlgebra ℝ L] [FiniteDimensional ℝ L] [LieRing.IsNilpotent L] : ∃ n : ℕ, Nonempty (TriangularAdjoint L n) := by … - theorem
OAI.PolycyclicRecognition.isPolycyclic_discrete_nilpotent_lieGroupline 40Source documentation
Every discrete subgroup is polycyclic; finite generation is a conclusion.
theorem isPolycyclic_discrete_nilpotent_lieGroup [LieRing.IsNilpotent (GroupLieAlgebra (𝓘(ℝ, E)) G)] (Γ : Subgroup G) [DiscreteTopology Γ] : IsPolycyclic Γ := by …Mentions: OAI.PolycyclicRecognition.IsPolycyclic