OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanWeightDilation.lean

GitHub source file

12 declarations, 0 contain sorry, 0 declared as axioms

Exact dilations of generalized Cartan weight spaces

Scalar multiplication by exp (χ h) on every generalized root space defines an actual Lie automorphism. The nilpotent parts of the Cartan action do not enter this construction. These are the exact weight dilations used in the box-translation argument.

  1. def OAI.PolycyclicRecognition.cartanWeightDecomposition line 28
  2. def OAI.PolycyclicRecognition.cartanWeightScale line 39

    Source documentation

    Scalar dilation on the actual generalized-root direct sum.

    def cartanWeightScale (h : H) : L →ₗ[ℝ] L := by
    …
  3. theorem OAI.PolycyclicRecognition.cartanWeightScale_apply_root line 45
  4. theorem OAI.PolycyclicRecognition.cartanWeightScale_apply_genWeight line 61

    Source documentation

    This also applies when the weight function is zero or its root space is zero; it does not require choosing a nonzero root vector.

    theorem cartanWeightScale_apply_genWeight (h : H) (χ : H → ℝ) {x : L}
        (hx : x ∈ genWeightSpace L χ) :
        cartanWeightScale T H h x = Real.exp (χ h) • x := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanWeightScale

  5. theorem OAI.PolycyclicRecognition.cartan_root_induction line 69
  6. theorem OAI.PolycyclicRecognition.cartanWeightScale_map_lie line 81

    Source documentation

    Addition of generalized weights makes the scalar dilation respect Lie brackets, even when the Cartan representation is not semisimple.

    theorem cartanWeightScale_map_lie (h : H) (x y : L) :
        cartanWeightScale T H h ⁅x, y⁆ =
          ⁅cartanWeightScale T H h x, cartanWeightScale T H h y⁆ := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanWeightScale

  7. theorem OAI.PolycyclicRecognition.cartanWeightScale_add_apply line 100
  8. theorem OAI.PolycyclicRecognition.cartanWeightScale_zero_apply line 113
  9. def OAI.PolycyclicRecognition.cartanWeightDilation line 123

    Source documentation

    Exact dilation as a Lie algebra automorphism, with inverse parameter -h.

    def cartanWeightDilation (h : H) : L ≃ₗ⁅ℝ⁆ L where
    …
  10. theorem OAI.PolycyclicRecognition.cartanWeightDilation_apply line 134
  11. theorem OAI.PolycyclicRecognition.cartanWeightDilation_mem_ideal line 138

    Source documentation

    Exact dilations preserve the nilpotent ideal generated by nonzero roots.

    theorem cartanWeightDilation_mem_ideal (h : H) {x : L} (hx : x ∈ cartanRootIdeal H) :
        cartanWeightDilation T H h x ∈ cartanRootIdeal H := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.cartanWeightDilation

  12. def OAI.PolycyclicRecognition.cartanIdealWeightDilation line 168

    Source documentation

    Restriction to the actual nilpotent Cartan ideal.

    def cartanIdealWeightDilation (h : H) : cartanRootIdeal H ≃ₗ⁅ℝ⁆ cartanRootIdeal H where
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal