OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanTrace.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Unimodularity on the Cartan ideal
The quotient of the ambient algebra by its nonzero-root ideal is generated by the nilpotent Cartan subalgebra. Its induced adjoint operators are nilpotent. Consequently restriction to the ideal preserves the trace.
- theorem
OAI.PolycyclicRecognition.cartan_quotient_ad_nilpotentline 25 - theorem
OAI.PolycyclicRecognition.trace_cartanRootIdeal_eq_zeroline 59Source documentation
The trace-zero action required by the support data follows from ambient unimodularity, even when the Cartan subgroup overlaps the root ideal.
theorem trace_cartanRootIdeal_eq_zero (hunimod : ∀ x : L, LinearMap.trace ℝ L (ad ℝ L x) = 0) (h : H) : LinearMap.trace ℝ (cartanRootIdeal H) (toEnd ℝ H (cartanRootIdeal H) h) = 0 := by …