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AlexKontorovich/PrimeNumberTheoremAnd
Source indexedlemma · leanprover/lean4:v4.32.0

summable_vonMangoldt_div_rpow

PrimeNumberTheoremAnd.Wiener · PrimeNumberTheoremAnd/Wiener.lean:3990 to 4010

Source documentation

The von Mangoldt function divided by n ^ s is summable for s > 1.

Exact Lean statement

lemma summable_vonMangoldt_div_rpow {s : ℝ} (hs : 1 < s) : Summable (fun n ↦ Λ n / n ^ s)

Complete declaration

Lean source

Canonical source
Full Lean sourceLean 4
lemma summable_vonMangoldt_div_rpow {s : } (hs : 1 < s) : Summable (fun n  Λ n / n ^ s) := by  have h_log_bound :  n : , (Λ n : )  Real.log n := fun n  vonMangoldt_le_log  suffices h_log_sum : Summable fun n :   Real.log n / (n : ) ^ s by    exact .of_nonneg_of_le (fun n  div_nonneg vonMangoldt_nonneg (by positivity))      (fun n  div_le_div_of_nonneg_right (h_log_bound n) (by positivity)) h_log_sum  have h_log_le_n_eps :  ε > 0,  C > 0,  n : , n  2  Real.log n / (n : ) ^ s  C * (n : ) ^- s) := by    intro ε hε_pos    obtain C, hC_pos, hC :  C > 0,  n : , n  2  Real.log n  C * (n : ) ^ ε := by      refine 1 / ε, by positivity, fun n hn  ?_      have := log_le_sub_one_of_pos (by positivity : 0 < (n : ) ^ ε)      rw [log_rpow (by positivity)] at this      nlinarith [rpow_pos_of_pos (by positivity : 0 < (n : )) ε, mul_div_cancel₀ 1 hε_pos.ne']    refine C, hC_pos, fun n hn  ?_    rw [rpow_sub (by positivity)]    exact le_trans (div_le_div_of_nonneg_right (hC n hn) (by positivity)) (by rw [div_eq_mul_inv]; ring_nf; norm_num)  obtain C, _, hC :  C > 0,  n : , n  2  Real.log n / (n : ) ^ s  C * (n : ) ^ ((s - 1) / 2 - s) :=    h_log_le_n_eps ((s - 1) / 2) (by linarith)  rw [ summable_nat_add_iff 2]  exact Summable.of_nonneg_of_le (fun n  div_nonneg (log_nonneg (by norm_cast; omega))    (rpow_nonneg (by positivity) _)) (fun n  hC _ (by omega)) (Summable.mul_left _ <| by      simpa using summable_nat_add_iff 2 |>.2 <| summable_nat_rpow.2 <| by linarith)