roseking's picture
Add lean source and binary files (part 96)
e9f356b verified
Raw History Blame Contribute Delete
20.7 kB
import Mathlib
import OAI.NumberTheory.CubicGram.CommonFactors
namespace OAI
/-! Finite cubic sieve operators, bilinear norms and coprime completion. -/
section
noncomputable section
open scoped BigOperators ContDiff
open Set Filter MeasureTheory Topology
attribute [local instance] Classical.propDecidable
namespace CubicFirstMoment
def primarySmoothedSieveMass (S : Finset Eisenstein) (u : Eisenstein → ℂ)
(W : ℝ → ℂ) (M : ℝ) : ℂ :=
∑' x : Eisenstein, if primary x then
W (norm x / M) * (‖∑ n ∈ S, u n * cubicSymbol n x‖^2 : ℝ) else 0
lemma primarySmoothedSieveMass_gram (S : Finset Eisenstein)
(hS : ∀ n ∈ S, primary n) (u : Eisenstein → ℂ)
(W : ℝ → ℂ) (hW : HasCompactSupport W) (hW' : ContDiff ℝ ∞ W)
{M : ℝ} (hM : 0 < M) :
primarySmoothedSieveMass S u W M =
∑ a ∈ S, ∑ b ∈ S, u a * star (u b) * primaryCharacterGram a b W M := by
let F (a b x : Eisenstein) : ℂ := u a * star (u b) *
(if primary x then W (norm x / M) * cubicSymbol a x * star (cubicSymbol b x) else 0)
have hF (a : Eisenstein) (ha : a ∈ S) (b : Eisenstein) (hb : b ∈ S) :
Summable (F a b) := by
apply Summable.mul_left
simpa only [and_true] using
summable_gram_restricted (hS a ha) (hS b hb) W hW hW' hM (fun _ => True)
have hpoint (x : Eisenstein) :
(if primary x then W (norm x / M) *
(‖∑ n ∈ S, u n * cubicSymbol n x‖^2 : ℝ) else 0) =
∑ a ∈ S, ∑ b ∈ S, F a b x := by
by_cases hx : primary x
· simp only [ite_eq_left hx, ← Complex.normSq_eq_norm_sq, ← Complex.mul_conj,
map_sum, map_mul, F]
simp_rw [Finset.sum_mul, Finset.mul_sum]
apply Finset.sum_congr rfl
intro a ha
apply Finset.sum_congr rfl
intro b hb
simp only [starRingEnd_apply]
ring
· simp [hx, F]
unfold primarySmoothedSieveMass
simp_rw [hpoint]
rw [Summable.tsum_finsetSum (fun a ha => summable_sum (fun b hb => hF a ha b hb))]
apply Finset.sum_congr rfl
intro a ha
rw [Summable.tsum_finsetSum (hF a ha)]
apply Finset.sum_congr rfl
intro b hb
exact tsum_mul_left
end CubicFirstMoment
open UniqueFactorizationMonoid
namespace CubicFirstMoment
lemma primaryPrime_mem_factors {n p : Eisenstein} (hn : primary n)
(hp : primaryPrime p) (hd : p ∣ n) : p ∈ primaryPrimeFactors n := by
obtain ⟨q,hq,hpq⟩ := exists_mem_normalizedFactors_of_dvd
(primary_ne_zero hn) hp.2.irreducible hd
apply Finset.mem_image.mpr
refine ⟨q, Multiset.mem_toFinset.mpr hq, ?_⟩
apply primary_associated_eq
(primaryNormalize_primary (unit_residue_of_dvd_primary hn (dvd_of_mem_normalizedFactors hq))) hp.1
exact (primaryNormalize_associated q).symm.trans hpq.symm
lemma primaryPrime_mem_factors_iff {n p : Eisenstein} (hn : primary n) :
p ∈ primaryPrimeFactors n ↔ primaryPrime p ∧ p ∣ n :=
⟨primaryPrimeFactor_spec hn, fun h => primaryPrime_mem_factors hn h.1 h.2⟩
lemma primeSet_subset_factors_of_prod_dvd {n : Eisenstein} (hn : primary n)
{s : Finset Eisenstein} (hs : ∀ p ∈ s, primaryPrime p)
(hd : (∏ p ∈ s, p) ∣ n) : s ⊆ primaryPrimeFactors n := by
intro p hp
exact primaryPrime_mem_factors hn (hs p hp)
((Finset.dvd_prod_of_mem (fun p : Eisenstein => p) hp).trans hd)
lemma primary_moebius_universal_indicator {U : Finset Eisenstein}
(hU : ∀ p ∈ U, primaryPrime p) {a b : Eisenstein}
(ha : primary a) (hsa : Squarefree a) (haU : primaryPrimeFactors a ⊆ U) :
(if IsCoprime a b then (1 : ℂ) else 0) =
∑ s ∈ U.powerset, (idealMoebius (∏ p ∈ s, p) : ℂ) *
(if (∏ p ∈ s, p) ∣ a ∧ (∏ p ∈ s, p) ∣ b then (1 : ℂ) else 0) := by
rw [primary_moebius_coprimality ha hsa]
calc
_ = ∑ s ∈ (primaryPrimeFactors a).powerset,
(idealMoebius (∏ p ∈ s, p) : ℂ) *
(if (∏ p ∈ s, p) ∣ a ∧ (∏ p ∈ s, p) ∣ b then (1 : ℂ) else 0) := by
apply Finset.sum_congr rfl
intro s hs
have hd : (∏ p ∈ s, p) ∣ a :=
(primary_subsets_prod_dvd ha (Finset.mem_powerset.mp hs) a).mpr
(fun p hp => (primaryPrimeFactor_spec ha (Finset.mem_powerset.mp hs hp)).2)
simp only [hd, true_and]
_ = _ := by
apply Finset.sum_subset (Finset.powerset_mono.mpr haU)
intro s hs hn
have hnd : ¬(∏ p ∈ s, p) ∣ a := by
intro hd
apply hn
exact Finset.mem_powerset.mpr (primeSet_subset_factors_of_prod_dvd ha
(fun p hp => hU p (Finset.mem_powerset.mp hs hp)) hd)
simp [hnd]
theorem coprime_bilinear_moebius (S T U : Finset Eisenstein)
(hS : ∀ a ∈ S, primary a ∧ Squarefree a)
(hU : ∀ p ∈ U, primaryPrime p)
(hSU : ∀ a ∈ S, primaryPrimeFactors a ⊆ U) (v w : Eisenstein → ℂ) :
(∑ a ∈ S, ∑ b ∈ T, if IsCoprime a b then v a * star (w b) else 0) =
∑ s ∈ U.powerset, (idealMoebius (∏ p ∈ s, p) : ℂ) *
(∑ a ∈ S, if (∏ p ∈ s, p) ∣ a then v a else 0) *
star (∑ b ∈ T, if (∏ p ∈ s, p) ∣ b then w b else 0) := by
have hpoint (a : Eisenstein) (ha : a ∈ S) (b : Eisenstein) :
(if IsCoprime a b then v a * star (w b) else 0) =
∑ s ∈ U.powerset, (idealMoebius (∏ p ∈ s, p) : ℂ) *
((if (∏ p ∈ s, p) ∣ a then v a else 0) *
star (if (∏ p ∈ s, p) ∣ b then w b else 0)) := by
have hi := congrArg (fun z : ℂ => z * (v a * star (w b)))
(primary_moebius_universal_indicator hU (hS a ha).1 (hS a ha).2 (hSU a ha)
(b := b))
rw [Finset.sum_mul] at hi
convert hi using 1
· split_ifs <;> simp
· apply Finset.sum_congr rfl
intro s hs
split_ifs <;> simp_all
simp_rw [Finset.sum_congr rfl (fun a ha => Finset.sum_congr rfl
(fun b _ => hpoint a ha b))]
simp_rw [Finset.sum_comm (s := T) (t := U.powerset)]
rw [Finset.sum_comm (s := S) (t := U.powerset)]
apply Finset.sum_congr rfl
intro s hs
simp only [star_sum]
simp only [Finset.sum_mul, Finset.mul_sum]
rw [Finset.sum_comm (s := T) (t := S)]
apply Finset.sum_congr rfl
intro a ha
apply Finset.sum_congr rfl
intro b hb
ring
end CubicFirstMoment
namespace CubicFirstMoment
def finiteCubicOperator (S H : Finset Eisenstein) :
EuclideanSpace ℂ S →L[ℂ] EuclideanSpace ℂ H :=
(Matrix.toEuclideanLin (fun (h : H) (a : S) => cubicSymbol a.val h.val)).toContinuousLinearMap
def finiteCubicBound (S H : Finset Eisenstein) : ℝ := ‖finiteCubicOperator S H‖^2
lemma finiteCubicBound_nonneg (S H : Finset Eisenstein) : 0 ≤ finiteCubicBound S H :=
sq_nonneg _
lemma finiteCubicOperator_apply (S H : Finset Eisenstein) (u : Eisenstein → ℂ)
(h : H) :
finiteCubicOperator S H (WithLp.toLp 2 (fun a : S => u a.val)) h =
∑ a ∈ S, u a * cubicSymbol a h.val := by
change (∑ a : S, cubicSymbol a.val h.val * u a.val) = _
rw [← Finset.sum_subtype S (fun _ => Iff.rfl) (fun a => cubicSymbol a h.val * u a)]
apply Finset.sum_congr rfl
intro a ha
ring
lemma finiteCubicBound_controls_mass (S H : Finset Eisenstein) (u : Eisenstein → ℂ) :
(∑ h ∈ H, ‖∑ a ∈ S, u a * cubicSymbol a h‖^2) ≤
finiteCubicBound S H * ∑ a ∈ S, ‖u a‖^2 := by
let v : EuclideanSpace ℂ S := WithLp.toLp 2 (fun a : S => u a.val)
have hb := (finiteCubicOperator S H).le_opNorm v
have hs := pow_le_pow_left₀ (_root_.norm_nonneg _) hb 2
rw [mul_pow, EuclideanSpace.norm_sq_eq, EuclideanSpace.norm_sq_eq] at hs
change (∑ h : H, ‖finiteCubicOperator S H v h‖^2) ≤
finiteCubicBound S H * ∑ a : S, ‖u a.val‖^2 at hs
dsimp only [v] at hs
simp_rw [finiteCubicOperator_apply] at hs
simpa only [← Finset.sum_subtype H (fun _ => Iff.rfl)
(fun h => ‖∑ a ∈ S, u a * cubicSymbol a h‖^2),
← Finset.sum_subtype S (fun _ => Iff.rfl) (fun a => ‖u a‖^2)] using hs
end CubicFirstMoment
namespace CubicFirstMoment
private def euclideanConj {ι : Type*} [Fintype ι] (v : EuclideanSpace ℂ ι) :
EuclideanSpace ℂ ι := WithLp.toLp 2 (fun i => star (v i))
private lemma euclideanConj_norm {ι : Type*} [Fintype ι] (v : EuclideanSpace ℂ ι) :
‖euclideanConj v‖ = ‖v‖ := by
apply (sq_eq_sq₀ (_root_.norm_nonneg _) (_root_.norm_nonneg _)).mp
simp [EuclideanSpace.norm_sq_eq, euclideanConj]
private def matrixHilbertOperator {ι κ : Type*} [Fintype ι] [Fintype κ]
(A : Matrix ι κ ℂ) : EuclideanSpace ℂ κ →L[ℂ] EuclideanSpace ℂ ι :=
A.toEuclideanLin.toContinuousLinearMap
private lemma matrixHilbertOperator_conj {ι κ : Type*} [Fintype ι] [Fintype κ]
(A : Matrix ι κ ℂ) (v : EuclideanSpace ℂ κ) :
matrixHilbertOperator (A.map star) v =
euclideanConj (matrixHilbertOperator A (euclideanConj v)) := by
apply PiLp.ext
intro i
change (∑ j, star (A i j) * v j) = star (∑ j, A i j * star (v j))
simp [star_sum, star_mul, mul_comm]
private lemma matrixHilbertOperator_conj_norm_le {ι κ : Type*} [Fintype ι] [Fintype κ]
(A : Matrix ι κ ℂ) :
‖matrixHilbertOperator (A.map star)‖ ≤ ‖matrixHilbertOperator A‖ := by
apply (ContinuousLinearMap.opNorm_le_iff (f := matrixHilbertOperator (A.map star))
(_root_.norm_nonneg (matrixHilbertOperator A))).mpr
intro v
rw [matrixHilbertOperator_conj, euclideanConj_norm]
simpa only [euclideanConj_norm] using
(matrixHilbertOperator A).le_opNorm (euclideanConj v)
private lemma matrixHilbertOperator_conj_norm {ι κ : Type*} [Fintype ι] [Fintype κ]
(A : Matrix ι κ ℂ) :
‖matrixHilbertOperator (A.map star)‖ = ‖matrixHilbertOperator A‖ := by
apply le_antisymm (matrixHilbertOperator_conj_norm_le A)
have he : (A.map star).map star = A := by ext i j; simp
have h := matrixHilbertOperator_conj_norm_le (A.map star)
rwa [he] at h
private lemma matrixHilbertOperator_transpose_norm {ι κ : Type*}
[Fintype ι] [Fintype κ] (A : Matrix ι κ ℂ) :
‖matrixHilbertOperator A.transpose‖ = ‖matrixHilbertOperator A‖ := by
have hc : A.transpose = (A.conjTranspose).map star := by
ext i j
simp
rw [hc, matrixHilbertOperator_conj_norm]
change ‖LinearMap.toContinuousLinearMap A.conjTranspose.toEuclideanLin‖ = _
rw [Matrix.toEuclideanLin_conjTranspose_eq_adjoint, LinearMap.adjoint_toContinuousLinearMap]
exact ContinuousLinearMap.adjoint.norm_map _
theorem finiteCubicBound_symm (S H : Finset Eisenstein)
(hS : ∀ a ∈ S, primary a) (hH : ∀ h ∈ H, primary h) :
finiteCubicBound S H = finiteCubicBound H S := by
let A : Matrix H S ℂ := fun h a => cubicSymbol a.val h.val
have hmat : (fun (a : S) (h : H) => cubicSymbol h.val a.val) = A.transpose := by
funext a h
exact cubic_reciprocity (hH h.val h.property) (hS a.val a.property)
unfold finiteCubicBound finiteCubicOperator
rw [hmat]
exact congrArg (fun x : ℝ => x^2) (matrixHilbertOperator_transpose_norm A).symm
end CubicFirstMoment
namespace CubicFirstMoment
theorem finiteCubicBound_bilinear (S H : Finset Eisenstein)
(v w phase : Eisenstein → ℂ) (hphase : ∀ h ∈ H, ‖phase h‖ ≤ 1) :
‖∑ h ∈ H, phase h * (∑ a ∈ S, v a * cubicSymbol a h) *
star (∑ a ∈ S, w a * cubicSymbol a h)‖ ≤
finiteCubicBound S H *
((∑ a ∈ S, ‖v a‖^2) + (∑ a ∈ S, ‖w a‖^2)) / 2 := by
let V (h : Eisenstein) := ∑ a ∈ S, v a * cubicSymbol a h
let W (h : Eisenstein) := ∑ a ∈ S, w a * cubicSymbol a h
calc
_ ≤ ∑ h ∈ H, ‖phase h * V h * star (W h)‖ := norm_sum_le _ _
_ ≤ ∑ h ∈ H, (‖V h‖^2+‖W h‖^2)/2 := by
apply Finset.sum_le_sum
intro h hh
rw [norm_mul, norm_mul, norm_star]
calc
_ ≤ 1 * ‖V h‖ * ‖W h‖ :=
mul_le_mul_of_nonneg_right
(mul_le_mul_of_nonneg_right (hphase h hh) (_root_.norm_nonneg _))
(_root_.norm_nonneg _)
_ ≤ _ := by nlinarith [sq_nonneg (‖V h‖-‖W h‖)]
_ = ((∑ h ∈ H, ‖V h‖^2) + (∑ h ∈ H, ‖W h‖^2))/2 := by
rw [← Finset.sum_div, Finset.sum_add_distrib]
_ ≤ _ := by
have hv := finiteCubicBound_controls_mass S H v
have hw := finiteCubicBound_controls_mass S H w
change (∑ h ∈ H, ‖V h‖^2) ≤ _ at hv
change (∑ h ∈ H, ‖W h‖^2) ≤ _ at hw
nlinarith
theorem finiteCubicBound_conjugate_bilinear (S H : Finset Eisenstein)
(v w phase : Eisenstein → ℂ) (hphase : ∀ h ∈ H, ‖phase h‖ ≤ 1) :
‖∑ h ∈ H, phase h * (∑ a ∈ S, v a * star (cubicSymbol a h)) *
star (∑ a ∈ S, w a * star (cubicSymbol a h))‖ ≤
finiteCubicBound S H *
((∑ a ∈ S, ‖v a‖^2) + (∑ a ∈ S, ‖w a‖^2)) / 2 := by
have h := finiteCubicBound_bilinear S H (fun a => star (w a))
(fun a => star (v a)) phase hphase
simp only [norm_star] at h
have he : (∑ h ∈ H, phase h * (∑ a ∈ S, v a * star (cubicSymbol a h)) *
star (∑ a ∈ S, w a * star (cubicSymbol a h))) =
∑ h ∈ H, phase h * (∑ a ∈ S, star (w a) * cubicSymbol a h) *
star (∑ a ∈ S, star (v a) * cubicSymbol a h) := by
apply Finset.sum_congr rfl
intro h hh
simp [star_sum, star_mul, mul_comm, mul_left_comm, mul_assoc]
rw [he]
simpa only [add_comm] using h
end CubicFirstMoment
namespace CubicFirstMoment
lemma coefficientVector_norm_sq (S : Finset Eisenstein) (u : Eisenstein → ℂ) :
‖(WithLp.toLp 2 (fun a : S => u a.val) : EuclideanSpace ℂ S)‖^2 =
∑ a ∈ S, ‖u a‖^2 := by
rw [EuclideanSpace.norm_sq_eq]
exact (Finset.sum_subtype S (fun _ => Iff.rfl) (fun a => ‖u a‖^2)).symm
lemma finiteCubicOperator_norm_sq (S H : Finset Eisenstein) (u : Eisenstein → ℂ) :
‖finiteCubicOperator S H (WithLp.toLp 2 (fun a : S => u a.val))‖^2 =
∑ h ∈ H, ‖∑ a ∈ S, u a * cubicSymbol a h‖^2 := by
rw [EuclideanSpace.norm_sq_eq]
change (∑ h : H, ‖finiteCubicOperator S H (WithLp.toLp 2 (fun a : S => u a.val)) h‖^2) = _
simp_rw [finiteCubicOperator_apply]
exact (Finset.sum_subtype H (fun _ => Iff.rfl)
(fun h => ‖∑ a ∈ S, u a * cubicSymbol a h‖^2)).symm
lemma finiteCubicBound_le_iff (S H : Finset Eisenstein) {C : ℝ} (hC : 0 ≤ C) :
finiteCubicBound S H ≤ C ↔ ∀ u : Eisenstein → ℂ,
(∑ h ∈ H, ‖∑ a ∈ S, u a * cubicSymbol a h‖^2) ≤
C * ∑ a ∈ S, ‖u a‖^2 := by
constructor
· intro h u
exact (finiteCubicBound_controls_mass S H u).trans
(mul_le_mul_of_nonneg_right h (Finset.sum_nonneg (fun _ _ => sq_nonneg _)))
· intro h
have hn : ‖finiteCubicOperator S H‖ ≤ Real.sqrt C := by
apply (ContinuousLinearMap.opNorm_le_iff (f := finiteCubicOperator S H)
(Real.sqrt_nonneg C)).mpr
intro v
let u (a : Eisenstein) : ℂ := if ha : a ∈ S then v ⟨a, ha⟩ else 0
have hv : WithLp.toLp 2 (fun a : S => u a.val) = v := by
apply PiLp.ext
intro a
simp [u]
have hh : ‖finiteCubicOperator S H v‖^2 ≤ C*‖v‖^2 := by
rw [← hv, finiteCubicOperator_norm_sq, coefficientVector_norm_sq]
exact h u
apply (sq_le_sq₀ (_root_.norm_nonneg _) (mul_nonneg (Real.sqrt_nonneg _) (_root_.norm_nonneg _))).mp
simpa only [mul_pow, Real.sq_sqrt hC] using hh
exact (pow_le_pow_left₀ (_root_.norm_nonneg _) hn 2).trans_eq (Real.sq_sqrt hC)
end CubicFirstMoment
namespace CubicFirstMoment
lemma finiteCubicBound_mono {S T H J : Finset Eisenstein} (hST : S ⊆ T) (hHJ : H ⊆ J) :
finiteCubicBound S H ≤ finiteCubicBound T J := by
apply (finiteCubicBound_le_iff S H (finiteCubicBound_nonneg T J)).mpr
intro u
let v (a : Eisenstein) := if a ∈ S then u a else 0
have hi (h : Eisenstein) : (∑ a ∈ T, v a * cubicSymbol a h) =
∑ a ∈ S, u a * cubicSymbol a h := by
calc
_ = ∑ a ∈ S, v a * cubicSymbol a h :=
(Finset.sum_subset hST (fun a _ ha => by simp [v, ha])).symm
_ = _ := Finset.sum_congr rfl (fun a ha => by simp [v, ha])
have hv : (∑ a ∈ T, ‖v a‖^2) = ∑ a ∈ S, ‖u a‖^2 := by
calc
_ = ∑ a ∈ S, ‖v a‖^2 :=
(Finset.sum_subset hST (fun a _ ha => by simp [v, ha])).symm
_ = _ := Finset.sum_congr rfl (fun a ha => by simp [v, ha])
have hb := finiteCubicBound_controls_mass T J v
simp_rw [hi, hv] at hb
exact (Finset.sum_le_sum_of_subset_of_nonneg hHJ (fun _ _ _ => sq_nonneg _)).trans hb
lemma finiteCubicBound_mul_support_le (Q H : Finset Eisenstein)
{m : Eisenstein} (hm : primary m) (hQ : ∀ b ∈ Q, primary b) :
finiteCubicBound (Q.image (fun b => m*b)) H ≤ finiteCubicBound Q H := by
apply (finiteCubicBound_le_iff _ _ (finiteCubicBound_nonneg Q H)).mpr
intro u
have hinj : ∀ a ∈ Q, ∀ b ∈ Q, m*a=m*b → a=b := by
intro a ha b hb he
exact mul_left_cancel₀ (primary_ne_zero hm) he
have he (h : Eisenstein) :
(∑ a ∈ Q.image (fun b => m*b), u a * cubicSymbol a h) =
cubicSymbol m h * ∑ b ∈ Q, u (m*b) * cubicSymbol b h := by
rw [Finset.sum_image hinj, Finset.mul_sum]
apply Finset.sum_congr rfl
intro b hb
rw [cubicSymbol_mul_lower (primary_ne_zero hm) (primary_ne_zero (hQ b hb))]
ring
have hn (h : Eisenstein) :
‖∑ a ∈ Q.image (fun b => m*b), u a * cubicSymbol a h‖^2 ≤
‖∑ b ∈ Q, u (m*b) * cubicSymbol b h‖^2 := by
rw [he, norm_mul]
apply pow_le_pow_left₀ (by positivity)
simpa only [one_mul] using mul_le_mul_of_nonneg_right
(norm_cubicSymbol_le_one hm h) (_root_.norm_nonneg _)
calc
_ ≤ ∑ h ∈ H, ‖∑ b ∈ Q, u (m*b) * cubicSymbol b h‖^2 :=
Finset.sum_le_sum (fun h _ => hn h)
_ ≤ finiteCubicBound Q H * ∑ b ∈ Q, ‖u (m*b)‖^2 :=
finiteCubicBound_controls_mass Q H (fun b => u (m*b))
_ = _ := by rw [Finset.sum_image hinj]
end CubicFirstMoment
namespace CubicFirstMoment
lemma norm_idealMoebius_le_one (m : Eisenstein) : ‖(idealMoebius m : ℂ)‖ ≤ 1 := by
have hs : (idealMoebius m : ℝ)^2 ≤ 1 := by
rw [idealMoebius_sq]
split_ifs <;> norm_num
have hn : ‖(idealMoebius m : ℂ)‖ = |(idealMoebius m : ℝ)| :=
Complex.norm_intCast _
rw [hn]
nlinarith [sq_abs (idealMoebius m : ℝ), abs_nonneg (idealMoebius m : ℝ)]
theorem finiteCubicBound_coprime_bilinear (S H U : Finset Eisenstein)
(hS : ∀ a ∈ S, primary a ∧ Squarefree a)
(hU : ∀ p ∈ U, primaryPrime p)
(hSU : ∀ a ∈ S, primaryPrimeFactors a ⊆ U)
(v w phase : Eisenstein → ℂ) (hphase : ∀ h ∈ H, ‖phase h‖ ≤ 1) :
‖∑ h ∈ H, phase h * ∑ a ∈ S, ∑ b ∈ S,
if IsCoprime a b then
(v a * star (cubicSymbol a h)) * star (w b * star (cubicSymbol b h)) else 0‖ ≤
∑ s ∈ U.powerset,
finiteCubicBound (S.filter (fun a => (∏ p ∈ s, p) ∣ a)) H *
((∑ a ∈ S.filter (fun a => (∏ p ∈ s, p) ∣ a), ‖v a‖^2) +
(∑ a ∈ S.filter (fun a => (∏ p ∈ s, p) ∣ a), ‖w a‖^2)) / 2 := by
let V (s : Finset Eisenstein) (h : Eisenstein) : ℂ :=
∑ a ∈ S.filter (fun a => (∏ p ∈ s, p) ∣ a), v a * star (cubicSymbol a h)
let W (s : Finset Eisenstein) (h : Eisenstein) : ℂ :=
∑ a ∈ S.filter (fun a => (∏ p ∈ s, p) ∣ a), w a * star (cubicSymbol a h)
have he (h : Eisenstein) := coprime_bilinear_moebius S S U hS hU hSU
(fun a => v a * star (cubicSymbol a h)) (fun a => w a * star (cubicSymbol a h))
have he' (h : Eisenstein) :
(∑ a ∈ S, ∑ b ∈ S, if IsCoprime a b then
(v a * star (cubicSymbol a h)) * star (w b * star (cubicSymbol b h)) else 0) =
∑ s ∈ U.powerset, (idealMoebius (∏ p ∈ s, p) : ℂ) * V s h * star (W s h) := by
simpa only [V, W, Finset.sum_filter] using he h
simp_rw [he', Finset.mul_sum]
rw [Finset.sum_comm]
have hfactor (s : Finset Eisenstein) :
(∑ h ∈ H, phase h * ((idealMoebius (∏ p ∈ s, p) : ℂ) * V s h * star (W s h))) =
(idealMoebius (∏ p ∈ s, p) : ℂ) * ∑ h ∈ H, phase h * V s h * star (W s h) := by
rw [Finset.mul_sum]
apply Finset.sum_congr rfl
intro h hh
ring
simp_rw [hfactor]
apply (norm_sum_le _ _).trans
apply Finset.sum_le_sum
intro s hs
rw [norm_mul]
calc
_ ≤ 1 * ‖∑ h ∈ H, phase h * V s h * star (W s h)‖ :=
mul_le_mul_of_nonneg_right (norm_idealMoebius_le_one _) (_root_.norm_nonneg _)
_ ≤ _ := by
rw [one_mul]
exact finiteCubicBound_conjugate_bilinear _ H v w phase hphase
end CubicFirstMoment
end
end
end OAI