File size: 8,023 Bytes
180bc03
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
import OAI.NumberTheory.TwoPointCorrelations.HalaszPrimeTheta
import OAI.NumberTheory.TwoPointCorrelations.MRTSmoothDistance

namespace OAI

/-! Prime discrepancy for the near-minimizing twist in MRT Appendix A.
The deleted-prime contribution is kept separate in Cauchy--Schwarz; this
retains the strict exponent needed by the renormalization error. -/

namespace TwoPointCorrelations

open Finset Filter
open scoped ComplexConjugate Classical

noncomputable def halaszPrimeDiscrepancy (F : ℕ → ℂ) (t : ℝ) (N : ℕ) : ℝ :=
  ∑ p ∈ primesUpTo N, ‖1 - F p * conj (mrtArchimedeanTwist t p)‖ / p

lemma halasz_one_sub_norm_sq {z : ℂ} (hz : ‖z‖ ≤ 1) :
    ‖1 - z‖ ^ 2 ≤ 2 * (1 - z.re) := by
  have hs : ‖z‖ ^ 2 ≤ 1 := by nlinarith [norm_nonneg z]
  simp only [Complex.sq_norm, Complex.normSq_apply, Complex.sub_re,
    Complex.sub_im, Complex.one_re, Complex.one_im] at hs ⊢
  nlinarith

lemma halasz_prime_unit_bound (F : ℕ → ℂ) (hF : OneBounded F)
    (t : ℝ) {N p : ℕ} (hp : p ∈ primesUpTo N) :
    ‖F p * conj (mrtArchimedeanTwist t p)‖ ≤ 1 := by
  rw [norm_mul, Complex.norm_conj, mrtArchimedeanTwist_norm, mul_one]
  exact hF p (mem_filter.mp hp).2.pos

lemma halasz_masked_discrepancy_split (F : ℕ → ℂ) (Q : Finset ℕ)
    (hQ : ∀ p ∈ Q, p.Prime) (t : ℝ) (N : ℕ) :
    halaszPrimeDiscrepancy (mrtMissingCoefficient F Q) t N =
      (∑ p ∈ (primesUpTo N).filter (fun p => p ∈ Q), (1 : ℝ) / p) +
      ∑ p ∈ (primesUpTo N).filter (fun p => p ∉ Q),
        ‖1 - F p * conj (mrtArchimedeanTwist t p)‖ / p := by
  unfold halaszPrimeDiscrepancy
  rw [← sum_filter_add_sum_filter_not (primesUpTo N) (fun p => p ∈ Q)]
  congr 1 <;> apply sum_congr rfl
  · intro p hp
    obtain ⟨hpN, hpQ⟩ := mem_filter.mp hp
    rw [mrtMissingCoefficient, mrtPrimeMask_prime Q hQ (mem_filter.mp hpN).2,
      ite_eq_left hpQ]
    simp
  · intro p hp
    obtain ⟨hpN, hpQ⟩ := mem_filter.mp hp
    rw [mrtMissingCoefficient, mrtPrimeMask_prime Q hQ (mem_filter.mp hpN).2,
      ite_eq_right hpQ]
    simp

lemma halasz_undeleted_discrepancy_sq (F : ℕ → ℂ) (hF : OneBounded F)
    (Q : Finset ℕ) (t : ℝ) (N : ℕ) :
    (∑ p ∈ (primesUpTo N).filter (fun p => p ∉ Q),
      ‖1 - F p * conj (mrtArchimedeanTwist t p)‖ / p) ^ 2 ≤
      2 * (∑ p ∈ (primesUpTo N).filter (fun p => p ∉ Q), (1 : ℝ) / p) *
        squaredDistance F (mrtArchimedeanTwist t) N := by
  let S := (primesUpTo N).filter (fun p => p ∉ Q)
  have hdef (p : ℕ) (hp : p ∈ primesUpTo N) :
      0 ≤ 1 - (F p * conj (mrtArchimedeanTwist t p)).re :=
    sub_nonneg.mpr ((Complex.re_le_norm _).trans (halasz_prime_unit_bound F hF t hp))
  have hh := sum_sq_le_sum_mul_sum_of_sq_le_mul S
    (r := fun p => ‖1 - F p * conj (mrtArchimedeanTwist t p)‖ / (p : ℝ))
    (f := fun p => (1 : ℝ) / p)
    (g := fun p => 2 * (1 - (F p * conj (mrtArchimedeanTwist t p)).re) / p)
    (fun _ _ => by positivity)
    (fun p hp => div_nonneg (mul_nonneg (by norm_num) (hdef p (mem_filter.mp hp).1))
      (Nat.cast_nonneg p)) (fun p hp => ?_)
  · have hd : (∑ p ∈ S, (1 - (F p * conj (mrtArchimedeanTwist t p)).re) / p) ≤
        squaredDistance F (mrtArchimedeanTwist t) N := by
      apply sum_le_sum_of_subset_of_nonneg (filter_subset _ _)
      intro p hp _
      exact div_nonneg (hdef p hp) (Nat.cast_nonneg p)
    have he : (∑ p ∈ S, 2 * (1 - (F p * conj (mrtArchimedeanTwist t p)).re) / p) =
        2 * ∑ p ∈ S, (1 - (F p * conj (mrtArchimedeanTwist t p)).re) / p := by
      rw [mul_sum]
      apply sum_congr rfl
      intro p _
      ring
    rw [he] at hh
    exact hh.trans (by
      have h := mul_le_mul_of_nonneg_left hd
        (show 0 ≤ 2 * ∑ p ∈ S, (1 : ℝ) / p by positivity)
      convert h using 1
      ring)
  · have hsq := halasz_one_sub_norm_sq (halasz_prime_unit_bound F hF t (mem_filter.mp hp).1)
    rw [div_pow]
    apply (div_le_div_of_nonneg_right hsq (sq_nonneg (p : ℝ))).trans_eq
    ring

lemma halasz_near_discrepancy_numeric (L A B Z D : ℝ) (hL : 0 ≤ L)
    (hAB : A ≤ B)
    (hAhi : A ≤ 51 / 100 * L) (hBhi : B ≤ 101 / 100 * L)
    (hD : D ≤ L / 8) (hZsq : Z ^ 2 ≤ 2 * (B - A) * D) :
    A + Z ≤ 7 / 8 * L := by
  have hm := mul_le_mul_of_nonneg_left hD (by linarith : 0 ≤ 2 * (B - A))
  have hprod : 0 ≤ (A - 51 / 100 * L) * (A - 99 / 100 * L) :=
    mul_nonneg_of_nonpos_of_nonpos (by linarith) (by linarith)
  by_contra hh
  have hz : 7 / 8 * L - A < Z := by linarith
  have hz0 : 0 ≤ 7 / 8 * L - A := by linarith
  have hs := mul_self_lt_mul_self hz0 hz
  nlinarith

/-- The `7/8` prime-discrepancy estimate used for near-twist renormalization.
Only primes below the actual Appendix-A cutoff may be deleted. -/
theorem halasz_near_masked_discrepancy :
    ∀ᶠ N : ℕ in atTop, ∀ (F : ℕ → ℂ), OneBounded F →
      ∀ (Q : Finset ℕ), (∀ p ∈ Q, p.Prime) →
      (∀ p ∈ Q, (p : ℝ) ≤ Real.exp (Real.sqrt (Real.log N))) →
      ∀ t : ℝ, squaredDistance F (mrtArchimedeanTwist t) N ≤
        Real.log (Real.log N) / 8 →
      halaszPrimeDiscrepancy (mrtMissingCoefficient F Q) t N ≤
        7 / 8 * Real.log (Real.log N) := by
  obtain ⟨C, hC⟩ := primeReciprocalInput
  have hlog : Tendsto (fun N : ℕ => Real.log N) atTop atTop :=
    Real.tendsto_log_atTop.comp tendsto_natCast_atTop_atTop
  have hll := (Real.tendsto_log_atTop.comp hlog).eventually
    (eventually_ge_atTop (100 * |C|))
  filter_upwards [hlog.eventually (eventually_ge_atTop (4 : ℝ)), hll] with N hl hllN
  dsimp only [Function.comp_def] at hllN
  intro F hF Q hQ hcut t hD
  let L := Real.log (Real.log N)
  let A := ∑ p ∈ (primesUpTo N).filter (fun p => p ∈ Q), (1 : ℝ) / p
  let B := ∑ p ∈ primesUpTo N, (1 : ℝ) / p
  let Z := ∑ p ∈ (primesUpTo N).filter (fun p => p ∉ Q),
    ‖1 - F p * conj (mrtArchimedeanTwist t p)‖ / p
  have hL : 0 ≤ L := by dsimp [L]; linarith [abs_nonneg C]
  have hCsmall : C ≤ L / 100 := by dsimp [L]; linarith [le_abs_self C]
  have hN1 : 1 < (N : ℝ) := (Real.log_pos_iff (Nat.cast_nonneg N)).mp (by linarith)
  have hN2 : (2 : ℝ) ≤ N := by
    have : 2 ≤ N := by exact_mod_cast hN1
    exact_mod_cast this
  have hB : B ≤ 101 / 100 * L := by
    have hh := (abs_le.mp (hC N hN2)).2
    rw [mrt_sievePrimesUpTo_nat] at hh
    dsimp [B, L]
    linarith
  have hsqrt : 2 ≤ Real.sqrt (Real.log N) := by
    have hs := Real.sq_sqrt (by linarith : 0 ≤ Real.log N)
    have hn := Real.sqrt_nonneg (Real.log N)
    nlinarith
  have hY2 : 2 ≤ Real.exp (Real.sqrt (Real.log N)) := by
    linarith [Real.add_one_le_exp (Real.sqrt (Real.log N))]
  have hA : A ≤ 51 / 100 * L := by
    have hsub : (primesUpTo N).filter (fun p => p ∈ Q) ⊆
        sievePrimesUpTo (Real.exp (Real.sqrt (Real.log N))) := by
      intro p hp
      obtain ⟨hpN, hpQ⟩ := mem_filter.mp hp
      exact mem_filter.mpr ⟨mem_Iic.mpr ((Nat.le_floor_iff (by positivity)).mpr
        (hcut p hpQ)), (mem_filter.mp hpN).2⟩
    have ha := sum_le_sum_of_subset_of_nonneg hsub
      (f := fun p : ℕ => (1 : ℝ) / p) (by intros; positivity)
    have hb := (abs_le.mp (hC _ hY2)).2
    rw [Real.log_exp, Real.log_sqrt (by linarith : 0 ≤ Real.log N)] at hb
    dsimp [A, L] at *
    linarith
  have hmass : (∑ p ∈ (primesUpTo N).filter (fun p => p ∉ Q), (1 : ℝ) / p) = B - A := by
    have hh := sum_filter_add_sum_filter_not (primesUpTo N) (fun p => p ∈ Q)
      (fun p : ℕ => (1 : ℝ) / p)
    dsimp [A, B]
    linarith
  have hAB : A ≤ B := by
    have hh : 0 ≤ ∑ p ∈ (primesUpTo N).filter (fun p => p ∉ Q), (1 : ℝ) / p := by positivity
    rw [hmass] at hh
    linarith
  have hZ := halasz_undeleted_discrepancy_sq F hF Q t N
  rw [hmass] at hZ
  have hh := halasz_near_discrepancy_numeric L A B Z
    (squaredDistance F (mrtArchimedeanTwist t) N) hL hAB hA hB hD hZ
  simpa only [halasz_masked_discrepancy_split F Q hQ t N, A, Z] using hh

end TwoPointCorrelations

end OAI