OAI/Combinatorics/SharpThreshold/BlockCapture.lean

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4 declarations, 0 contain sorry, 0 declared as axioms

Averaging and capture of nonnegative spectral mass

For any finite family of nonnegative masses and random detection events, if every low-degree support is detected with probability at least a, an upper bound on the average detected mass bounds the low-degree mass.

  1. theorem OAI.Problem313.weighted_capture_sum_swap line 24

    Source documentation

    Interchange averaging over blocks and summing the mass of captured supports.

    theorem weighted_capture_sum_swap
        (w : β → ℝ) (mass : ι → ℝ) (detect : β → ι → Prop)
        [DecidableRel detect] :
        (∑ b, w b * ∑ i, if detect b i then mass i else 0) =
          ∑ i, (∑ b, if detect b i then w b else 0) * mass i := by
    …
  2. theorem OAI.Problem313.capture_mass_mul_le line 38

    Source documentation

    A pointwise detection lower bound controls the mass on any chosen finite set.

    theorem capture_mass_mul_le
        (low : Finset ι) (mass detection : ι → ℝ) (a : ℝ)
        (hmass : ∀ i, 0 ≤ mass i) (hdet : ∀ i, 0 ≤ detection i)
        (hlow : ∀ i ∈ low, a ≤ detection i) :
        a * ∑ i ∈ low, mass i ≤ ∑ i, detection i * mass i := by
    …
  3. theorem OAI.Problem313.averaged_capture_mass_mul_le line 52

    Source documentation

    The same capture inequality stated directly with finite block averaging.

    theorem averaged_capture_mass_mul_le
        (low : Finset ι) (w : β → ℝ) (mass : ι → ℝ)
        (detect : β → ι → Prop) [DecidableRel detect] (a : ℝ)
        (hw : ∀ b, 0 ≤ w b) (hmass : ∀ i, 0 ≤ mass i)
        (hlow : ∀ i ∈ low, a ≤ ∑ b, if detect b i then w b else 0) :
        a * ∑ i ∈ low, mass i ≤
          ∑ b, w b * ∑ i, if detect b i then mass i else 0 := by
    …
  4. theorem OAI.Problem313.block_capture_mass_le line 71

    Source documentation

    Cancel the random-block detection factor. The factor 4 is exactly the ratio between the edge-touch upper bound 2*m/n and detection m/(2*n).

    theorem block_capture_mass_le
        (low : Finset ι) (w : β → ℝ) (mass : ι → ℝ)
        (detect : β → ι → Prop) [DecidableRel detect]
        (m n Q : ℝ) (hm : 0 < m) (hn : 0 < n)
        (hw : ∀ b, 0 ≤ w b) (hmass : ∀ i, 0 ≤ mass i)
        (hlow : ∀ i ∈ low, m / (2 * n) ≤ ∑ b, if detect b i then w b else 0)
        (haverage : (∑ b, w b * ∑ i, if detect b i then mass i else 0) ≤
          (2 * m / n) * Q) :
        (∑ i ∈ low, mass i) ≤ 4 * Q := by
    …