On complemented subspaces of L1[0,1]L_1[0,1]

PL1/IntrinsicSpikeFamilies.lean

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1import PL1.IntrinsicHeadRepresentatives2import PL1.IntrinsicSpikeAverages3import PL1.IntrinsicSpikes4import PL1.TailSpikeMultiplication5import PL1.DaugavetAveraging67/-!8# Actual finite spike families in the intrinsic space910Finite head representatives, genuine tail families, Haar independence and the11proved resolvent commutator discharge every input to the intrinsic coordinate12estimates. The resulting family lives in the original dyadic intrinsic graph.13-/1415noncomputable section16open MeasureTheory17open scoped ENNReal NNReal BigOperators1819namespace PL1.IntrinsicSpikeFamilies20open Noise Walsh IntrinsicGraph IntrinsicHeadRepresentatives21open FiniteCoordinateKernels L1Multiplication2223variable {K : Type*} [RCLike K]2425theorem coordinate_norm_preserved {rates : ℕ → ℝ≥0} {d : ℕ}26    {T : PositiveTime} {δ : ℝ} (Q : TailSpikes.RateFamily rates d T δ)27    (a : Assignments Q.coordinates) {f : (dyadicSystem K rates).IntrinsicSpace}28    (hf : f ∈ (intrinsicExpectation K rates d).range) (n : ℕ) :29    ‖multiplier K (Q.q a) (coord (dyadicSystem K rates).analysis n f)‖ =30      ‖coord (dyadicSystem K rates).analysis n f‖ := by31  obtain ⟨F, hF, hFeq⟩ := continuousRepresentative_coord_of_range rates d n hf32  rw [← hFeq]33  exact HeadTail.norm_multiplier_toLp_of_density Q.beyond_prefix.symm F (Q.q a)34    hF (Q.q_depends a) (ae_of_all _ (Q.nonnegative a)) (Q.integral_one a)3536theorem coordinate_separation {rates : ℕ → ℝ≥0} {d : ℕ}37    {T : PositiveTime} {δ : ℝ} (Q : TailSpikes.RateFamily rates d T δ)38    (a : Assignments Q.coordinates) {h f : (dyadicSystem K rates).IntrinsicSpace}39    (hh : h ∈ (intrinsicExpectation K rates d).range)40    (hf : f ∈ (intrinsicExpectation K rates d).range) (n : ℕ) :41    (1 - 2 * δ) * (‖coord (dyadicSystem K rates).analysis n h‖ +42        ‖coord (dyadicSystem K rates).analysis n f‖) ≤43      ‖coord (dyadicSystem K rates).analysis n h +44        multiplier K (Q.q a) (coord (dyadicSystem K rates).analysis n f)‖ := by45  obtain ⟨H, hH, hHeq⟩ := continuousRepresentative_coord_of_range rates d n hh46  obtain ⟨F, hF, hFeq⟩ := continuousRepresentative_coord_of_range rates d n hf47  rw [← hHeq, ← hFeq]48  exact HeadTail.concentration_multiplier_toLp Q.beyond_prefix.symm H F (Q.q a)49    hH hF (Q.q_depends a) (ae_of_all _ (Q.nonnegative a)) (Q.integral_one a)50    (Q.B a) (Q.measurable a) δ (Q.small a).le (Q.concentrated a).le5152theorem coordinate_commutator {rates : ℕ → ℝ≥0} {d : ℕ}53    {T : PositiveTime} {δ : ℝ} (Q : TailSpikes.RateFamily rates d T δ)54    (a : Assignments Q.coordinates) {f : (dyadicSystem K rates).IntrinsicSpace}55    (hf : f ∈ (intrinsicExpectation K rates d).range) :56    ∀ n, ‖(dyadicSystem K rates).analysis n57          (multiplier K (Q.q a) (evalZero (dyadicSystem K rates).analysis f)) -58        multiplier K (Q.q a) (coord (dyadicSystem K rates).analysis n f)‖ ≤59      IntrinsicSpikes.error T ‖evalZero (dyadicSystem K rates).analysis f‖ n := by60  apply IntrinsicSpikes.coordinate_commutator_le rates (multiplier K (Q.q a)) f T61  obtain ⟨F, hF, hFeq⟩ := continuousRepresentative_evalZero_of_range rates d hf62  intro t63  rw [← hFeq]64  exact Q.norm_id_sub_resolvent_commutator_le a F hF t6566/-- The actual products have exact finite average, the manuscript's norm bound,67and its separation estimate, without residual analytic assumptions. -/68theorem exists_products {rates : ℕ → ℝ≥0} {d : ℕ}69    {T : PositiveTime} {δ : ℝ} (Q : TailSpikes.RateFamily rates d T δ)70    (h f : (dyadicSystem K rates).IntrinsicSpace)71    (hh : h ∈ (intrinsicExpectation K rates d).range)72    (hf : f ∈ (intrinsicExpectation K rates d).range) :73    ∃ g : Assignments Q.coordinates → (dyadicSystem K rates).IntrinsicSpace,74      (∀ a, evalZero (dyadicSystem K rates).analysis (g a) =75        multiplier K (Q.q a) (evalZero (dyadicSystem K rates).analysis f)) ∧76      (Fintype.card (Assignments Q.coordinates) : K)⁻¹ • (∑ a, g a) = f ∧77      (∀ a, |‖g a‖ - ‖f‖| ≤78        IntrinsicSpikes.eta T * ‖evalZero (dyadicSystem K rates).analysis f‖) ∧79      (∀ a, (1 - 2 * δ) * (‖h‖ + ‖f‖) -80        IntrinsicSpikes.eta T * ‖evalZero (dyadicSystem K rates).analysis f‖ ≤ ‖h + g a‖) := by81  have hex (a : Assignments Q.coordinates) := IntrinsicSpikes.exists_product rates82    (multiplier K (Q.q a)) f T (coordinate_norm_preserved Q a hf)83    (coordinate_commutator Q a hf)84  choose g hge hgn using hex85  refine ⟨g, hge, ?_, hgn, ?_⟩86  · have havg := IntrinsicSpikeAverages.average_products K Q (dyadicSystem K rates).analysis f g hge87    have hsmul : (Fintype.card (Assignments Q.coordinates) : ℝ)⁻¹ • (∑ a, g a) =88        (((Fintype.card (Assignments Q.coordinates) : ℝ)⁻¹ : ℝ) : K) • (∑ a, g a) := by89      apply Subtype.ext90      change (Fintype.card (Assignments Q.coordinates) : ℝ)⁻¹ •91          ((∑ a, g a : (dyadicSystem K rates).IntrinsicSpace) : Ambient (Y := Lp K 1 haar)) =92        (((Fintype.card (Assignments Q.coordinates) : ℝ)⁻¹ : ℝ) : K) •93          ((∑ a, g a : (dyadicSystem K rates).IntrinsicSpace) : Ambient (Y := Lp K 1 haar))94      exact RCLike.real_smul_eq_coe_smul (K := K) _ _95    rw [hsmul] at havg96    simpa only [RCLike.ofReal_inv, RCLike.ofReal_natCast] using havg97  · intro a98    exact IntrinsicSpikes.separation rates (multiplier K (Q.q a)) h f (g a) (hge a) T δ99      (coordinate_separation Q a hh hf) (coordinate_commutator Q a hf)100101/-- Existence of genuine tail families supplies exactly the finite-family102criterion on the original finite-coordinate intrinsic ranges. -/103theorem finiteSpikeFamilies (rates : ℕ → ℝ≥0)104    (hQ : ∀ (d : ℕ) (T : PositiveTime) (δ : ℝ), 0 < δ →105      Nonempty (TailSpikes.RateFamily rates d T δ)) :106    Daugavet.FiniteSpikeFamilies K (dyadicSystem K rates).IntrinsicSpace107      (fun n => (intrinsicExpectation K rates n).range) := by108  classical109  intro d h hh f hf δ hδ η hη110  obtain ⟨T, hT⟩ := IntrinsicSpikes.exists_eta_lt hη111  obtain ⟨Q⟩ := hQ d T δ hδ112  obtain ⟨g, hge, havg, hgn, hgs⟩ := exists_products Q h f hh hf113  let e := Fintype.equivFin (Assignments Q.coordinates)114  refine ⟨Fintype.card (Assignments Q.coordinates), Fintype.card_pos, fun i => g (e.symm i),115    ?_, ?_, ?_⟩116  · rw [e.symm.sum_comp]117    exact havg118  · intro a119    have he : IntrinsicSpikes.eta T * ‖evalZero (dyadicSystem K rates).analysis f‖ ≤120        η * ‖f‖ := mul_le_mul hT.le (norm_evalZero_le _ _) (norm_nonneg _) hη.le121    have hn := (abs_le.mp (hgn (e.symm a))).2122    nlinarith123  · intro a124    have he : IntrinsicSpikes.eta T * ‖evalZero (dyadicSystem K rates).analysis f‖ ≤125        η * ‖f‖ := mul_le_mul hT.le (norm_evalZero_le _ _) (norm_nonneg _) hη.le126    linarith [hgs (e.symm a)]127128end PL1.IntrinsicSpikeFamilies129