OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanTrace.lean

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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.

  1. theorem OAI.PolycyclicRecognition.cartan_quotient_ad_nilpotent line 25
  2. theorem OAI.PolycyclicRecognition.trace_cartanRootIdeal_eq_zero line 59

    Source 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
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal