OAI/Analysis/ModularTheory/FourierCompression.lean

GitHub source file

13 declarations, 0 contain sorry, 0 declared as axioms

Fourier transport of the scalar compression of the modular core. This produces a unital completely positive contraction commuting with every character multiplier. It does not postulate a core trace.

  1. def OAI.WeakPureInfiniteness.modularFourierInclusion line 19

    Source documentation

    The scalar inclusion in Fourier coordinates is an actual Hilbert-space isometry, rather than a formal change of spectral variables.

    def modularFourierInclusion : Lp ℂ 2 (volume : Measure ℝ) →ₗᵢ[ℂ]
        Lp H 2 (volume : Measure ℝ) :=
    …
  2. lemma OAI.WeakPureInfiniteness.modularFourierInclusion_apply line 24
  3. lemma OAI.WeakPureInfiniteness.modularFourierInclusion_adjoint line 27
  4. def OAI.WeakPureInfiniteness.modularFourierCompression line 37

    Source documentation

    Scalar compression after Fourier diagonalization.

    def modularFourierCompression : (Lp H 2 (volume : Measure ℝ) →L[ℂ]
        Lp H 2 (volume : Measure ℝ)) →L[ℂ]
          (Lp ℂ 2 (volume : Measure ℝ) →L[ℂ] Lp ℂ 2 (volume : Measure ℝ)) :=
    …
  5. lemma OAI.WeakPureInfiniteness.modularFourierCompression_apply line 42
  6. lemma OAI.WeakPureInfiniteness.modularFourierCompression_conjugate line 49
  7. theorem OAI.WeakPureInfiniteness.modularFourierCompression_cp line 57
  8. theorem OAI.WeakPureInfiniteness.modularFourierCompression_contractive line 60
  9. theorem OAI.WeakPureInfiniteness.modularFourierCompression_one line 69
  10. lemma OAI.WeakPureInfiniteness.fourierConjugation_translation line 72
  11. theorem OAI.WeakPureInfiniteness.modularFourierCompression_commutes line 86

    Source documentation

    The Fourier compression of every core element commutes with every character multiplier, including on the full von Neumann closure.

    theorem modularFourierCompression_commutes (T : Lp H 2 (volume : Measure ℝ) →L[ℂ]
        Lp H 2 (volume : Measure ℝ))
        (hT : T ∈ modularCrossedProduct (volume : Measure ℝ) S) (r : ℝ) :
        Commute (modularFourierCompression S T)
          (modularDualUnitary (H := ℂ) (volume : Measure ℝ) r :
    …

    Mentions: OAI.WeakPureInfiniteness.modularCrossedProduct, OAI.WeakPureInfiniteness.modularFourierCompression, OAI.WeakPureInfiniteness.modularDualUnitary

  12. lemma OAI.WeakPureInfiniteness.modularScalarCompression_coefficient_translate line 106
  13. lemma OAI.WeakPureInfiniteness.modularFourierCompression_coefficient_translate line 127

    Source documentation

    The Fourier coefficient of a crossed-product monomial is the original vector-state coefficient times the corresponding character multiplier.

    lemma modularFourierCompression_coefficient_translate (T : H →L[ℂ] H) (s : ℝ) :
        modularFourierCompression S
          (modularLpRepresentation volume S.D T *
            (modularLpTranslateEquiv (H := H) volume s :
    …

    Mentions: OAI.WeakPureInfiniteness.modularFourierCompression, OAI.WeakPureInfiniteness.modularLpRepresentation, OAI.WeakPureInfiniteness.modularLpTranslateEquiv