OAI/Combinatorics/SparsestCut/WeightNormalization.lean

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Normalization of finite weights

A lower approximation to a probability law retains coordinatewise domination and setwise lower bounds after normalization. These are the retained-demand estimates in Section 7 of OpenAI's Constant-factor hardness of uniform sparsest cut.

  1. def OAI.UniformSparsestCut.FiniteWeights.normalized line 24
  2. theorem OAI.UniformSparsestCut.FiniteWeights.normalized_nonneg line 26
  3. theorem OAI.UniformSparsestCut.FiniteWeights.normalized_total line 30
  4. theorem OAI.UniformSparsestCut.FiniteWeights.normalized_mass line 35
  5. theorem OAI.UniformSparsestCut.FiniteWeights.normalized_le_twice line 44

    Source documentation

    Normalization of a sufficiently large lower approximation increases each weight by at most a factor of two.

    theorem normalized_le_twice {μ l : ι → ℝ} {ε : ℝ}
        (hμ : ∀ i, 0 ≤ μ i) (hle : ∀ i, l i ≤ μ i)
        (hε : ε ≤ 1 / 2) (hL : 1 - ε ≤ total l) :
        ∀ i, normalized l i ≤ 2 * μ i := by
    …

    Mentions: OAI.UniformSparsestCut.FiniteWeights.total, OAI.UniformSparsestCut.FiniteWeights.normalized

  6. theorem OAI.UniformSparsestCut.FiniteWeights.normalized_event_lower line 55

    Source documentation

    Every finite event loses at most the discarded mass after normalization.

    theorem normalized_event_lower {μ l : ι → ℝ} {ε : ℝ}
        (hl : ∀ i, 0 ≤ l i) (hle : ∀ i, l i ≤ μ i) (hμ₁ : total μ = 1)
        (hε : ε ≤ 1 / 2) (hL : 1 - ε ≤ total l) (E : Finset ι) :
        (∑ i ∈ E, μ i) - ε ≤ ∑ i ∈ E, normalized l i := by
    …

    Mentions: OAI.UniformSparsestCut.FiniteWeights.total, OAI.UniformSparsestCut.FiniteWeights.normalized