The mean-square estimate from the canonical energy estimate
ProvedQRH.dual_to_mean_squareAssume the canonical estimate for the completed dual energy family: there is k with E(H, X, F) <= k (X F)^eps X F for all admissible scales 1 <= H <= X <= F. Assume the Poisson-summation reduction hpred: every such uniform bound on the energy converts into the mean-square bound msSum over the rows of norm at most D^(1+theta) with column scale D and truncation 2D, bounded by k D^(2 + theta + eps) for all D >= 2. Then there is k with msSum <= k D^(2 + theta + eps) for all D >= 2: the mean-square estimate of Proposition 3.1 of the source follows from the canonical energy estimate.
import Mathlib import Definitions.Def_QRH_arith import Definitions.Def_QRH_sums import Definitions.Def_QRH_lfun
universe u
namespace QRH
/-- The reduction of the mean-square estimate of Proposition 3.1 to the
canonical energy estimate for the completed dual family. The first
hypothesis is the canonical estimate of sections 5 and 6 of the source —
proved there from the quadratic large sieve, the theta transformation,
and the admissible-exponent descent: the energy E(H, X, F) is bounded by
(XF)^ε XF uniformly over the admissible scales. The second hypothesis is
the Poisson-summation reduction of section 4: expanding the square and
applying Poisson summation in the row converts the canonical estimate at
the dual scales into the mean-square estimate at the original scales,
with row range D^(1+θ), column scale D, and truncation 2D. The theorem
assembles the two: the mean-square estimate of Proposition 3.1 follows.
-/
theorem dual_to_mean_square (W : QRHWorld.{u}) (S : QRHSums W)
(c : W.E → ℂ) (Wt : ℝ → ℂ)
(θ ε : ℝ) (hθ : 0 < θ) (hθ₁ : θ ≤ 1 / 10) (hε : 0 < ε)
(hcan : ∃ k : ℝ, ∀ H X F : ℝ, 1 ≤ H → H ≤ X → X ≤ F →
Eener W S c Wt H X F ≤ k * (X * F) ^ ε * X * F)
(hpred : ∀ k : ℝ, (∀ H X F : ℝ, 1 ≤ H → H ≤ X → X ≤ F →
Eener W S c Wt H X F ≤ k * (X * F) ^ ε * X * F) →
∀ D : ℝ, 2 ≤ D →
msSum W S c Wt (D ^ (1 + θ)) D (2 * D) ≤ k * D ^ (2 + θ + ε)) :
∃ k : ℝ, ∀ D : ℝ, 2 ≤ D →
msSum W S c Wt (D ^ (1 + θ)) D (2 * D) ≤ k * D ^ (2 + θ + ε) := by
sorry
end QRH
Read-back
What the Lean code literally says, in plain math · glm-5-latest-short
Read-back (self-check authored by the same model that produced the statement): the formal theorem takes 0 < theta <= 1/10, eps > 0, the canonical hypothesis hcan (a constant k bounding Eener by k (X F)^eps X F on 1 <= H <= X <= F), and the reduction hypothesis hpred mapping every such canonical constant to the mean-square bound at the original scales, and produces a constant k with msSum W S c Wt (D ^ (1 + theta)) D (2 * D) <= k * D ^ (2 + theta + eps) for D >= 2. The proof instantiates hpred at the constant of hcan; no arithmetic of the world beyond the two hypotheses is used.