AlexKontorovich/PrimeNumberTheoremAnd
Source indexedtheorem · leanprover/lean4:v4.32.0
riemannZetaLogDerivResidue
PrimeNumberTheoremAnd.ZetaBounds · PrimeNumberTheoremAnd/ZetaBounds.lean:578 to 623
Source documentation
As a corollary, the log derivative of the Riemann zeta function has a simple pole at :
Exact Lean statement
@[blueprint
(title := "riemannZetaLogDerivResidue")
(statement := /--
The log derivative of the Riemann zeta function $\zeta(s)$ has a simple pole at $s=1$ with
residue $-1$: $-\frac{\zeta'(s)}{\zeta(s)} - \frac{1}{s-1} = O(1)$.
-/)
(proof := /--
This follows from Theorem \ref{logDerivResidue} and Theorem \ref{riemannZetaResidue}.
-/)]
theorem riemannZetaLogDerivResidue :
∃ U ∈ 𝓝 1, BddAbove (norm ∘ (-(ζ' / ζ) - (fun s ↦ (s - 1)⁻¹)) '' (U \ {1}))Complete declaration
Lean source
Full Lean sourceLean 4
@[blueprint (title := "riemannZetaLogDerivResidue") (statement := /-- The log derivative of the Riemann zeta function $\zeta(s)$ has a simple pole at $s=1$ with residue $-1$: $-\frac{\zeta'(s)}{\zeta(s)} - \frac{1}{s-1} = O(1)$. -/) (proof := /-- This follows from Theorem \ref{logDerivResidue} and Theorem \ref{riemannZetaResidue}. -/)]theorem riemannZetaLogDerivResidue : ∃ U ∈ 𝓝 1, BddAbove (norm ∘ (-(ζ' / ζ) - (fun s ↦ (s - 1)⁻¹)) '' (U \ {1})) := by obtain ⟨U,U_in_nhds, hU⟩ := riemannZetaResidue have hU' : BddAbove (norm ∘ (ζ - fun s ↦ 1 * (s - 1)⁻¹) '' (U \ {1})) := by simp only [Function.comp_apply, Pi.sub_apply, one_mul] at hU ⊢ exact hU obtain ⟨V,V_in_nhds, V_is_open, hV⟩ := nonZeroOfBddAbove U_in_nhds one_ne_zero hU' let W := V ∩ interior U have hW : ∀ s ∈ W \ {1}, ζ s ≠ 0 := by intro s hs have s_in_V_diff : s ∈ V \ {1} := ⟨hs.1.1, hs.2⟩ exact hV s s_in_V_diff have ζ_holc: HolomorphicOn ζ (W \ {1}) := by intro y hy simp only [Set.mem_sdiff, mem_singleton_iff] at hy refine DifferentiableAt.differentiableWithinAt ?_ apply differentiableAt_riemannZeta hy.2 have W_in_nhds : W ∈ 𝓝 1 := by refine inter_mem V_in_nhds ?_ exact interior_mem_nhds.mpr U_in_nhds have := logDerivResidue'' hW ζ_holc W_in_nhds one_ne_zero have HW : BddAbove (norm ∘ (ζ - fun s ↦ (s - 1)⁻¹) '' (W \ {1})) := by obtain ⟨c, hc⟩ := bddAbove_def.mp hU apply bddAbove_def.mpr use c rintro y ⟨x, x_in_W, fxy⟩ apply hc exact ⟨x, ⟨interior_subset x_in_W.1.2, x_in_W.2⟩, fxy⟩ simp only [one_mul] at this have aux: ∀ a, ‖-(deriv ζ a / ζ a) - (a - 1)⁻¹‖ = ‖(deriv ζ a / ζ a) + (a - 1)⁻¹‖ := by intro a calc ‖-(deriv ζ a / ζ a) - (a - 1)⁻¹‖ = ‖-((deriv ζ a / ζ a) + (a - 1)⁻¹)‖ := by ring_nf _ = ‖(deriv ζ a / ζ a) + (a - 1)⁻¹‖ := by rw [norm_neg] simp only [Function.comp_apply, Pi.sub_apply] at hU simp only [Function.comp_apply, Pi.sub_apply, Pi.neg_apply, Pi.div_apply, aux] apply this HW