The capped estimate from convexity

TheoremNonpositivity of a convex function from its endpoint values#✓fully proved

A convex function on [0, 1] that is nonpositive at both endpoints is nonpositive on [0, 1]. See also ConvexOn.le_max_of_mem_Icc.

theorem cvg_convexGap_le {G : ℝ → ℝ} (hG : ConvexOn ℝ (Icc (0 : ℝ) 1) G)
    (h0 : G 0 ≤ 0) (h1 : G 1 ≤ 0) {u : ℝ} (hu0 : 0 ≤ u) (hu1 : u ≤ 1) :
    G u ≤ 0
Used by 1

TheoremFinite sum of convex functions is convex#✓fully proved

A finite sum of convex functions is convex.

theorem cvg_convexOn_sum {α : Type*} (s : Finset α) (g : α → ℝ → ℝ) {D : Set ℝ}
    (hD : Convex ℝ D) (hg : ∀ a ∈ s, ConvexOn ℝ D (g a)) :
    ConvexOn ℝ D (fun u => ∑ a ∈ s, g a u)
Used by 1

TheoremConvexity of \((1 - u)^k\) on \((0, 1)\)#✓fully proved

u ↦ (1 - u)^k is convex on [0, 1].

theorem cvg_oneSubPow_convexOn (k : ℕ) :
    ConvexOn ℝ (Icc (0 : ℝ) 1) (fun u : ℝ => (1 - u) ^ k)
Used by 1

TheoremConvexity of the damped total weight#✓fully proved

The damped total weight u ↦ ∑_S 4 |S| (1-u)^{|S|-1} f̂(S)² is convex on [0, 1].

theorem cvg_L_convexOn (p : ℝ) (φ : ConfigSpace ι → Bool) :
    ConvexOn ℝ (Icc (0 : ℝ) 1)
      (fun u => ∑ S : Finset ι, 4 * (S.card : ℝ) * (1 - u) ^ (S.card - 1)
        * (ptn_coeff p (fun ω => if φ ω then (1 : ℝ) else 0) S) ^ 2)
Uses 4 · Used by 1

TheoremConcavity of \(\exp(m u/(2-u))\) for \(-1 \le m \le 0\)#✓fully proved

u ↦ exp (m · u/(2-u)) is concave on [0, 1] for -1 ≤ m ≤ 0.

theorem cvg_Q_concaveOn {m : ℝ} (hm0 : m ≤ 0) (hm1 : -1 ≤ m) :
    ConcaveOn ℝ (Icc (0 : ℝ) 1) (fun u : ℝ => Real.exp (m * (u / (2 - u))))
Used by 1

TheoremConcavity of \(\delta^{u/(2-u)} T\) for \(e^{-1} \le \delta \le 1\)#✓fully proved

u ↦ δ^{u/(2-u)} T is concave on [0, 1] for e^{-1} ≤ δ ≤ 1 and T ≥ 0.

theorem cvg_R_concaveOn {δ T : ℝ} (hδlo : Real.exp (-1) ≤ δ) (hδhi : δ ≤ 1) (hT : 0 ≤ T) :
    ConcaveOn ℝ (Icc (0 : ℝ) 1) (fun u : ℝ => δ ^ (u / (2 - u)) * T)
Uses 1 · Used by 1

TheoremCapped estimate on \((0, 1)\) from concavity of the right side#✓fully proved

If the right side of the capped estimate is concave in u, the estimate holds on (0, 1).

theorem cvg_openResidue_of_concaveR [Nonempty ι] {p : ℝ} (hp0 : 0 < p) (hp1 : p < 1)
    (φ : ConfigSpace ι → Bool)
    (hconc : ConcaveOn ℝ (Icc (0 : ℝ) 1)
      (fun u => (maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0))
        ^ (u / (2 - u)) * totalInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)))
    {u : ℝ} (hu0 : 0 < u) (hu1 : u < 1) :
    (∑ S : Finset ι, 4 * (S.card : ℝ) * (1 - u) ^ (S.card - 1)
        * (ptn_coeff p (fun ω => if φ ω then (1 : ℝ) else 0) S) ^ 2)
      ≤ (maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)) ^ (u / (2 - u))
        * totalInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)
Uses 9 · Used by 1

TheoremMaximal influence of a Boolean function is at most one#✓fully proved

The maximal influence of a Boolean function is at most 1.

theorem cvg_maxInfl_le_one [Nonempty ι] {p : ℝ} (hp0 : 0 ≤ p) (hp1 : p ≤ 1)
    (φ : ConfigSpace ι → Bool) :
    maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0) ≤ 1
Uses 9 · Used by 1

TheoremCapped estimate when the maximal influence is at least \(e^{-1}\)#✓fully proved

The capped estimate holds for all u ∈ (0, 1) when the maximal influence is at least e^{-1}.

theorem cvg_openResidue_largeDelta [Nonempty ι] {p : ℝ} (hp0 : 0 < p) (hp1 : p < 1)
    (φ : ConfigSpace ι → Bool)
    (hδlo : Real.exp (-1) ≤ maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0))
    {u : ℝ} (hu0 : 0 < u) (hu1 : u < 1) :
    (∑ S : Finset ι, 4 * (S.card : ℝ) * (1 - u) ^ (S.card - 1)
        * (ptn_coeff p (fun ω => if φ ω then (1 : ℝ) else 0) S) ^ 2)
      ≤ (maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)) ^ (u / (2 - u))
        * totalInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)
Uses 14 · Used by 1

DefinitionSmall-influence residual case of the capped estimate#✓fully proved

The capped estimate for all p ∈ (1/2, q) with p < 1, all Boolean functions with maximal influence δ < e^{-1}, and all u ∈ (0, 1).

def cvg_smallDeltaResidue (q : ℝ) : Prop :=
  ∀ p ∈ Set.Ioo (1 / 2 : ℝ) q, p < 1 → ∀ {E : Type} [Fintype E] [DecidableEq E] [Nonempty E]
    (φ : ConfigSpace E → Bool),
      maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0) < Real.exp (-1) →
      ∀ u : ℝ, 0 < u → u < 1 →
      (∑ S : Finset E, 4 * (S.card : ℝ) * (1 - u) ^ (S.card - 1)
          * (ptn_coeff p (fun ω => if φ ω then (1 : ℝ) else 0) S) ^ 2)
        ≤ (maxInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)) ^ (u / (2 - u))
          * totalInfl (OSSS.bernoulliWeight p) (fun ω => if φ ω then (1 : ℝ) else 0)
Uses 5 · Used by 4

TheoremSmall-influence case implies the open-interval case#✓fully proved

cvg_smallDeltaResidue q implies frh_openResidue q.

theorem cvg_openResidue_of_smallDelta {q : ℝ}
    (H : cvg_smallDeltaResidue q) : frh_openResidue q
Uses 8 · Used by 1

TheoremSmall-influence case implies the full capped estimate on \((1/2, q)\)#✓fully proved

cvg_smallDeltaResidue q implies mxd_martingaleHC_statement q.

theorem cvg_martingaleHC_of_smallDelta {q : ℝ}
    (H : cvg_smallDeltaResidue q) : mxd_martingaleHC_statement q
Uses 4 · Used by 2
12 fully proved

The dependency explorer needs JavaScript and its graph data.

Download the complete graph data.