OAI/Analysis/LipschitzHilbert/Fourier/Projection.lean

GitHub source file

17 declarations, 0 contain sorry, 0 declared as axioms

Projection of the near-resonant quadruple measure

The quantile-gap argument in §7 projects the triple weight on quadruples to coordinates (i,k,l). Unique completion makes the Hellinger affinity of the projected measures exactly the affinity before projection.

  1. abbrev OAI.LipschitzHilbert.PhaseCombinatorics.Triple line 22
  2. def OAI.LipschitzHilbert.PhaseCombinatorics.insertSecond line 24
  3. def OAI.LipschitzHilbert.PhaseCombinatorics.projectedMass line 30
  4. def OAI.LipschitzHilbert.PhaseCombinatorics.independentMass line 34
  5. theorem OAI.LipschitzHilbert.PhaseCombinatorics.resonant_event_completion_lt line 38

    Source documentation

    The quantile event forces its resonant completion below the selected central half interval. This is the geometric step behind the event deficit.

    theorem resonant_event_completion_lt {frequency : ι → ℝ} {gap a b e h : ℝ}
        (hgap : 0 < gap) (hab : gap ≤ b - a) (heh : h - e ≤ (b - a) / 2)
        {i j k l : ι} (hr : Resonant frequency gap i j k l)
        (hi : b ≤ frequency i) (hk : frequency k ≤ a) (hl : frequency l ≤ h) :
        frequency j < e := by
    …

    Mentions: OAI.LipschitzHilbert.PhaseCombinatorics.Resonant

  6. theorem OAI.LipschitzHilbert.PhaseCombinatorics.projectedMass_nonneg line 46
  7. theorem OAI.LipschitzHilbert.PhaseCombinatorics.independentMass_nonneg line 51
  8. theorem OAI.LipschitzHilbert.PhaseCombinatorics.sum_projectedMass_eq line 55
  9. theorem OAI.LipschitzHilbert.PhaseCombinatorics.sum_projectedMass_le_one line 64
  10. theorem OAI.LipschitzHilbert.PhaseCombinatorics.sum_independentMass_eq_one line 72
  11. theorem OAI.LipschitzHilbert.PhaseCombinatorics.sqrt_sum_mul_of_unique_support line 79

    Source documentation

    With at most one nonzero summand, taking this square root commutes with the sum exactly.

    theorem sqrt_sum_mul_of_unique_support [Fintype ι] (a : ι → ℝ) (b : ℝ)
        (hunique : ∀ i j, a i ≠ 0 → a j ≠ 0 → i = j) :
        Real.sqrt ((∑ i, a i) * b) = ∑ i, Real.sqrt (a i * b) := by
    …
  12. theorem OAI.LipschitzHilbert.PhaseCombinatorics.marginal_unique_support line 101
  13. theorem OAI.LipschitzHilbert.PhaseCombinatorics.marginal_mul_permuted_eq_independent line 114
  14. theorem OAI.LipschitzHilbert.PhaseCombinatorics.projected_affinity_eq line 128

    Source documentation

    The projection preserves the affinity, because each projected point has at most one possible resonant completion.

    theorem projected_affinity_eq [Fintype ι]
        {frequency : ι → ℝ} {gap : ℝ} (hgap : 0 < gap)
        (hsep : Separated frequency gap) (x : ι → ℝ) :
        (∑ q : Triple ι,
          Real.sqrt (projectedMass frequency gap x q * independentMass x q)) =
          ∑ q : Quadruple ι, Real.sqrt
            (marginal frequency gap x q * marginal frequency gap x (swapPairs q)) := by
    …

    Mentions: OAI.LipschitzHilbert.PhaseCombinatorics.Separated, OAI.LipschitzHilbert.PhaseCombinatorics.Triple, OAI.LipschitzHilbert.PhaseCombinatorics.projectedMass, OAI.LipschitzHilbert.PhaseCombinatorics.independentMass, OAI.LipschitzHilbert.PhaseCombinatorics.Quadruple, OAI.LipschitzHilbert.PhaseCombinatorics.marginal, OAI.LipschitzHilbert.PhaseCombinatorics.swapPairs

  15. theorem OAI.LipschitzHilbert.PhaseCombinatorics.resonanceSum_nonneg line 159
  16. theorem OAI.LipschitzHilbert.PhaseCombinatorics.resonanceSum_sq_le_projected_affinity line 165

    Source documentation

    The bound in exactly the affinity convention used for finite probabilities.

    theorem resonanceSum_sq_le_projected_affinity [Fintype ι]
        {frequency : ι → ℝ} {gap : ℝ} (hgap : 0 < gap)
        (hsep : Separated frequency gap) (x : ι → ℝ)
        (hx : ∀ i, 0 ≤ x i) (hsum : ∑ i, x i = 1) :
        resonanceSum frequency gap x ^ 2 ≤
          affinity (projectedMass frequency gap x) (independentMass x) := by
    …

    Mentions: OAI.LipschitzHilbert.PhaseCombinatorics.Separated, OAI.LipschitzHilbert.PhaseCombinatorics.resonanceSum, OAI.LipschitzHilbert.affinity, OAI.LipschitzHilbert.PhaseCombinatorics.projectedMass, OAI.LipschitzHilbert.PhaseCombinatorics.independentMass

  17. theorem OAI.LipschitzHilbert.PhaseCombinatorics.resonanceSum_gap_of_event_deficit line 185

    Source documentation

    Any event with a definite deficit between the projected and independent triple laws gives the quantitative improvement in the fourth-moment sum.

    theorem resonanceSum_gap_of_event_deficit [Fintype ι]
        {frequency : ι → ℝ} {gap : ℝ} (hgap : 0 < gap)
        (hsep : Separated frequency gap) (x : ι → ℝ)
        (hx : ∀ i, 0 ≤ x i) (hsum : ∑ i, x i = 1)
        (s : Finset (Triple ι)) {g : ℝ} (hg : 0 ≤ g)
        (hdeficit : g ≤ ∑ q ∈ s,
          (independentMass x q - projectedMass frequency gap x q)) :
        resonanceSum frequency gap x ≤ 1 - g ^ 2 / 4 := by
    …

    Mentions: OAI.LipschitzHilbert.PhaseCombinatorics.Separated, OAI.LipschitzHilbert.PhaseCombinatorics.Triple, OAI.LipschitzHilbert.PhaseCombinatorics.independentMass, OAI.LipschitzHilbert.PhaseCombinatorics.projectedMass, OAI.LipschitzHilbert.PhaseCombinatorics.resonanceSum