OAI/GroupTheory/Kervaire/HaarCurrents.lean

GitHub source file

17 declarations, 0 contain sorry, 0 declared as axioms

  1. lemma OAI.KervaireHaarFlow.hasCompactSupport_of_compact line 28
  2. lemma OAI.KervaireHaarFlow.continuous_integrable line 32
  3. lemma OAI.KervaireHaarFlow.hasDerivAt_integral_compact line 37

    Source documentation

    Compactness supplies the domination needed for differentiation with respect to a real parameter. This lemma only assumes actual joint continuity and actual pointwise derivatives.

    lemma hasDerivAt_integral_compact {f df : ℝ → S → E}
        (hf : Continuous (Function.uncurry f)) (hd : Continuous (Function.uncurry df))
        (hfd : ∀ t x, HasDerivAt (fun u ↦ f u x) (df t x) t) (t : ℝ) :
        HasDerivAt (fun u ↦ ∫ x, f u x ∂μ) (∫ x, df t x ∂μ) t := by
    …
  4. lemma OAI.KervaireHaarFlow.integral_deriv_eq_zero_of_invariant line 58

    Source documentation

    The infinitesimal form of invariance under a measure-preserving flow.

    lemma integral_deriv_eq_zero_of_invariant {f df : ℝ → S → E}
        (hf : Continuous (Function.uncurry f)) (hd : Continuous (Function.uncurry df))
        (hfd : ∀ t x, HasDerivAt (fun u ↦ f u x) (df t x) t)
        (hinv : ∀ t, (∫ x, f t x ∂μ) = ∫ x, f 0 x ∂μ) (t : ℝ) :
        (∫ x, df t x ∂μ) = 0 := by
    …
  5. lemma OAI.KervaireClosedCurrent.contDiff_multilinear_eval line 79

    Source documentation

    Smoothness of simultaneous evaluation, including a varying multilinear map.

    lemma contDiff_multilinear_eval {n : ℕ}
        {f : E → ContinuousMultilinearMap ℝ (fun _ : Fin n ↦ E) F}
        {V : Fin n → E → E} (hf : ContDiff ℝ ∞ f) (hV : ∀ i, ContDiff ℝ ∞ (V i)) :
        ContDiff ℝ ∞ (fun x ↦ f x (V · x)) := by
    …
  6. lemma OAI.KervaireClosedCurrent.contDiff_eval_fields line 108

    Source documentation

    Evaluation of a smooth form on smooth vector fields is smooth.

    lemma contDiff_eval_fields {n : ℕ} {form : E → E [⋀^Fin n]→L[ℝ] F}
        {V : Fin n → E → E} (hf : ContDiff ℝ ∞ form) (hV : ∀ i, ContDiff ℝ ∞ (V i)) :
        ContDiff ℝ ∞ (fun x ↦ form x (V · x)) := by
    …
  7. lemma OAI.KervaireCurrentHomotopy.integral_eval_constant line 128

    Source documentation

    A moving-frame homotopy formula for a closed current, proved from the actual exterior derivative identity and differentiation under a compact-parameter integral.

    lemma integral_eval_constant {n : ℕ} {e : S → E} (he : Continuous e)
        {form : (ℝ × E) → (ℝ × E) [⋀^Fin (n+1)]→L[ℝ] ℝ}
        (hf : ContDiff ℝ ∞ form)
        {V : Fin (n+2) → (ℝ × E) → (ℝ × E)} (hV : ∀ i, ContDiff ℝ ∞ (V i))
        (hVzero : ∀ p, V 0 p = (1, 0))
        (hdiv : ∀ (t : ℝ) (i : Fin (n+2)), i ≠ 0 → ∀ (g : (ℝ × E) → ℝ),
          ContDiff ℝ ∞ g →
          (∫ x, fderiv ℝ g (t,e x) (V i (t,e x)) ∂μ) = 0)
        (hbracket : ∀ (t : ℝ) (x : S) (i j : Fin (n+1)), i ≤ j →
          form (t,e x) (Matrix.vecCons (lieBracket ℝ (V i.castSucc) (V j.succ) (t,e x))
            (j.removeNth (i.castSucc.removeNth (fun l ↦ V l (t,e x))))) = 0)
        (hclosed : ∀ (t : ℝ) (x : S),
    …
  8. def OAI.KervaireHaarFlow.expFlow line 200

    Source documentation

    The genuine exponential flow in the unitary group.

    def expFlow (a : skewAdjoint.submodule ℝ B) (t : ℝ) : unitary B :=
    …
  9. lemma OAI.KervaireHaarFlow.integral_unitary_fderiv_mul_eq_zero line 211

    Source documentation

    Right-invariant vector fields on a compact unitary group have zero Haar divergence. The derivative is the ambient Fréchet derivative.

    lemma integral_unitary_fderiv_mul_eq_zero {g : B → ℝ} (hg : ContDiff ℝ ∞ g)
        (a : skewAdjoint.submodule ℝ B) :
        (∫ x : unitary B, fderiv ℝ g (x : B) ((x : B) * a) ∂μ) = 0 := by
    …
  10. def OAI.KervaireUnitaryHaarCurrent.liftField line 240

    Source documentation

    The autonomous lift of a right-translation field to the time cylinder.

    def liftField (a : B) : (ℝ × B) →L[ℝ] (ℝ × B) :=
    …
  11. lemma OAI.KervaireUnitaryHaarCurrent.liftField_apply line 244
  12. lemma OAI.KervaireUnitaryHaarCurrent.bracket_lift line 246
  13. lemma OAI.KervaireUnitaryHaarCurrent.bracket_time_lift line 252
  14. lemma OAI.KervaireUnitaryHaarCurrent.bracket_lift_time line 256
  15. lemma OAI.KervaireUnitaryHaarCurrent.integral_liftField_eq_zero line 265
  16. lemma OAI.KervaireCompactUnitary.isCompact_unitary line 285
  17. lemma OAI.KervaireCompactUnitary.compactSpace line 293

    Source documentation

    The unitary group of a finite-dimensional complex C⋆-algebra is compact.

    lemma compactSpace : CompactSpace (unitary B) :=
    …