Summable kernels for the corrected comparison #
Multiplying the coprime majorant by the product of prime increments produces
a convolution kernel. Its positive local terms are exactly the weighted tails
proved convergent in ComparisonLocal.
The convolution kernel used in the arithmetic-weight comparison.
Equations
- NairTenenbaum.comparisonKernel U l n = U n * NairTenenbaum.radicalProduct l n
Instances For
theorem
NairTenenbaum.comparisonKernel_smooth_hasSum
{U l : ℕ → ℝ}
(hU₀ : U 0 = 0)
(hU₁ : U 1 = 1)
(hU : ∀ (n : ℕ), 0 ≤ U n)
(hl : ∀ (p : ℕ), 0 ≤ l p)
(hmul : ∀ (m n : ℕ), m.Coprime n → U (m * n) = U m * U n)
(hs : ∀ (p : ℕ), Nat.Prime p → Summable fun (ν : ℕ) => U (p ^ ν))
(s : Finset ℕ)
:
HasSum (fun (n : ↑(Nat.factoredNumbers s)) => comparisonKernel U l ↑n)
(∏ p ∈ s with Nat.Prime p, (1 + kernelLocalError U l p))
Exact finite Euler product for the auxiliary convolution kernel.
theorem
NairTenenbaum.comparisonKernel_sum_le_product
{U l : ℕ → ℝ}
(hU₀ : U 0 = 0)
(hU₁ : U 1 = 1)
(hU : ∀ (n : ℕ), 0 ≤ U n)
(hl : ∀ (p : ℕ), 0 ≤ l p)
(hmul : ∀ (m n : ℕ), m.Coprime n → U (m * n) = U m * U n)
(hs : ∀ (p : ℕ), Nat.Prime p → Summable fun (ν : ℕ) => U (p ^ ν))
(N : ℕ+)
:
∑ n ∈ Finset.Icc 1 N, comparisonKernel U l ↑n ≤ ∏ p ∈ Finset.range (↑N + 1) with Nat.Prime p, (1 + kernelLocalError U l p)
A kernel partial sum is bounded by its finite Euler product.
theorem
NairTenenbaum.kernelLocalError_product_le
{U l : ℕ → ℝ}
(hU : ∀ (n : ℕ), 0 ≤ U n)
(hl : ∀ (p : ℕ), 0 ≤ l p)
(hs : Summable fun (p : Nat.Primes) => kernelLocalError U l ↑p)
(s : Finset ℕ)
:
∏ p ∈ s with Nat.Prime p, (1 + kernelLocalError U l p) ≤ Real.exp (∑' (p : Nat.Primes), kernelLocalError U l ↑p)
The finite Euler products have a uniform bound if their local errors are summable. The bound is independent of the cutoff.
theorem
NairTenenbaum.unitary_comparison_uniform
{w : ℕ+ → ℝ}
{U l : ℕ → ℝ}
(hw₀ : ∀ (n : ℕ+), 0 ≤ w n)
(hU₀ : U 0 = 0)
(hU₁ : U 1 = 1)
(hU : ∀ (n : ℕ), 0 ≤ U n)
(hl : ∀ (p : ℕ), 0 ≤ l p)
(hmul : ∀ (m n : ℕ), m.Coprime n → U (m * n) = U m * U n)
(hw : ∀ (a b : ℕ+), (↑a).Coprime ↑b → w (a * b) ≤ U ↑a * w b)
(hs : ∀ (p : ℕ), Nat.Prime p → Summable fun (ν : ℕ) => U (p ^ ν))
(hE : Summable fun (p : Nat.Primes) => kernelLocalError U l ↑p)
(N : ℕ+)
:
∑ n ∈ Finset.Icc 1 N, w n * radicalProduct (fun (p : ℕ) => 1 + l p) ↑n ≤ Real.exp (∑' (p : Nat.Primes), kernelLocalError U l ↑p) * ∑ n ∈ Finset.Icc 1 N, w n
A corrected global comparison for scalar weights, with explicit sufficient hypotheses on their coprime majorant and prime increments.