import Mathlib import OAI.MathematicalPhysics.BFSS.OscillatorForms namespace OAI /-! Weighted Sobolev form closure and normal oscillator nonnegativity. -/ namespace BFSSSliceSobolev noncomputable section open MeasureTheory Set Filter Topology variable {E F : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E] [FiniteDimensional ℝ E] [MeasurableSpace E] [BorelSpace E] [NormedAddCommGroup F] [InnerProductSpace ℝ F] [CompleteSpace F] variable (μ : Measure E) [IsFiniteMeasureOnCompacts μ] variable {ι : Type*} [Fintype ι] (e : ι → E) def weightedToL2 (w : E → ℝ) (hw : Continuous w) (f : Core (E := E) (F := F)) : Lp F 2 μ := ((hw.smul f.continuous).memLp_of_hasCompactSupport f.hasCompactSupport.smul_left).toLp (fun x => w x • f x) omit [FiniteDimensional ℝ E] [CompleteSpace F] in lemma weightedToL2_ae (w : E → ℝ) (hw : Continuous w) (f : Core (E := E) (F := F)) : (weightedToL2 μ w hw f : E → F) =ᵐ[μ] fun x => w x • f x := MemLp.coeFn_toLp _ def weightedClosure (w : E → ℝ) (hw : Continuous w) : Set (Lp F 2 μ × Gradient (F := F) μ (ι := ι) × Lp F 2 μ) := closure (Set.range fun f : Core (E := E) (F := F) => (toL2 μ f,gradient μ e f,weightedToL2 μ w hw f)) def coreMul (χ : Core (E := E) (F := ℝ)) (f : Core (E := E) (F := F)) : Core (E := E) (F := F) := ⟨fun x => χ x • f x,χ.contDiff.smul f.contDiff,f.hasCompactSupport.smul_left, by intro x hx; trivial⟩ omit [FiniteDimensional ℝ E] [MeasurableSpace E] [BorelSpace E] [CompleteSpace F] in lemma coreMul_apply (χ : Core (E := E) (F := ℝ)) (f : Core (E := E) (F := F)) (x : E) : coreMul χ f x = χ x • f x := rfl omit [FiniteDimensional ℝ E] [MeasurableSpace E] [BorelSpace E] [CompleteSpace F] in lemma coreMul_derivative (χ : Core (E := E) (F := ℝ)) (f : Core (E := E) (F := F)) (v : E) (x : E) : (TestFunction.lineDerivCLM (k := ⊤) ℝ v (coreMul χ f)) x = χ x • (TestFunction.lineDerivCLM (k := ⊤) ℝ v f) x + (TestFunction.lineDerivCLM (k := ⊤) ℝ v χ) x • f x := by change fderiv ℝ (fun x => χ x • f x) x v = χ x • fderiv ℝ (f : E → F) x v + fderiv ℝ (χ : E → ℝ) x v • f x rw [fderiv_fun_smul (χ.contDiff.differentiable (by simp) x) (f.contDiff.differentiable (by simp) x)] rfl abbrev scalarMul (χ : Core (E := E) (F := ℝ)) (u : Lp F 2 μ) : Lp F 2 μ := BFSSLocalL2.compactMul χ χ.continuous χ.hasCompactSupport u def cutoffGradient (χ : Core (E := E) (F := ℝ)) (u : Lp F 2 μ) (v : Gradient (F := F) μ (ι := ι)) : Gradient (F := F) μ (ι := ι) := WithLp.toLp 2 (fun j => scalarMul μ χ (v j) + scalarMul μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) χ) u) def cutoffMoment (w : E → ℝ) (hw : Continuous w) (χ : Core (E := E) (F := ℝ)) (u : Lp F 2 μ) : Lp F 2 μ := BFSSLocalL2.compactMul (fun x => w x * χ x) (hw.mul χ.continuous) χ.hasCompactSupport.mul_left u omit [FiniteDimensional ℝ E] [CompleteSpace F] [IsFiniteMeasureOnCompacts μ] [Fintype ι] in lemma cutoffGradient_continuous (χ : Core (E := E) (F := ℝ)) : Continuous (fun p : Lp F 2 μ × Gradient (F := F) μ (ι := ι) => cutoffGradient μ e χ p.1 p.2) := by apply (PiLp.continuous_toLp 2 _).comp apply continuous_pi intro j exact ((BFSSLocalL2.compactMul_continuous _ _ _).comp ((PiLp.continuous_apply 2 _ j).comp continuous_snd)).add ((BFSSLocalL2.compactMul_continuous _ _ _).comp continuous_fst) omit [FiniteDimensional ℝ E] [CompleteSpace F] [Fintype ι] in lemma cutoff_core_tuple (w : E → ℝ) (hw : Continuous w) (χ : Core (E := E) (F := ℝ)) (f : Core (E := E) (F := F)) : (toL2 μ (coreMul χ f),gradient μ e (coreMul χ f),weightedToL2 μ w hw (coreMul χ f)) = (scalarMul μ χ (toL2 μ f),cutoffGradient μ e χ (toL2 μ f) (gradient μ e f), cutoffMoment μ w hw χ (toL2 μ f)) := by apply Prod.ext · apply Lp.ext filter_upwards [toL2_ae μ (coreMul χ f),BFSSLocalL2.compactMul_ae χ χ.continuous χ.hasCompactSupport (toL2 μ f),toL2_ae μ f] with x h₁ h₂ h₃ rw [h₁,h₂,h₃,coreMul_apply] apply Prod.ext · apply PiLp.ext intro j apply Lp.ext filter_upwards [toL2_ae μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) (coreMul χ f)), BFSSLocalL2.compactMul_ae χ χ.continuous χ.hasCompactSupport (gradient μ e f j), BFSSLocalL2.compactMul_ae _ _ _ (toL2 μ f), toL2_ae μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) f),toL2_ae μ f, Lp.coeFn_add (scalarMul μ χ (gradient μ e f j)) (scalarMul μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) χ) (toL2 μ f))] with x h₁ h₂ h₃ h₄ h₅ h₆ change (toL2 μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) (coreMul χ f)) : E → F) x = ((scalarMul μ χ (gradient μ e f j) + scalarMul μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) χ) (toL2 μ f) : Lp F 2 μ) : E → F) x rw [h₁,h₆,Pi.add_apply,h₂,h₃,gradient_apply,h₄,h₅,coreMul_derivative] · apply Lp.ext filter_upwards [weightedToL2_ae μ w hw (coreMul χ f), BFSSLocalL2.compactMul_ae (fun x => w x*χ x) (hw.mul χ.continuous) χ.hasCompactSupport.mul_left (toL2 μ f), toL2_ae μ f] with x h₁ h₂ h₃ change (weightedToL2 μ w hw (coreMul χ f) : E → F) x = (BFSSLocalL2.compactMul (fun x => w x*χ x) (hw.mul χ.continuous) χ.hasCompactSupport.mul_left (toL2 μ f) : E → F) x rw [h₁,h₂,h₃,coreMul_apply,mul_smul] omit [FiniteDimensional ℝ E] [CompleteSpace F] in lemma cutoff_mem_weightedClosure (w : E → ℝ) (hw : Continuous w) (χ : Core (E := E) (F := ℝ)) {u : Lp F 2 μ} {v : Gradient (F := F) μ (ι := ι)} (hp : (u,v) ∈ closedGraph μ e) : (scalarMul μ χ u,cutoffGradient μ e χ u v,cutoffMoment μ w hw χ u) ∈ weightedClosure μ e w hw := by change (u,v) ∈ closure (Set.range fun f : Core (E := E) (F := F) => (toL2 μ f,gradient μ e f)) at hp obtain ⟨p,hp,ht⟩ := mem_closure_iff_seq_limit.mp hp choose f hf using hp have hf₂ : Tendsto (fun n => (toL2 μ (f n),gradient μ e (f n))) atTop (𝓝 (u,v)) := by simpa only [hf] using ht have hf₁ : Tendsto (fun n => toL2 μ (f n)) atTop (𝓝 u) := (continuous_fst.tendsto (u,v)).comp hf₂ apply mem_closure_of_tendsto (b := (atTop : Filter ℕ)) (f := fun n => (scalarMul μ χ (toL2 μ (f n)),cutoffGradient μ e χ (toL2 μ (f n)) (gradient μ e (f n)), cutoffMoment μ w hw χ (toL2 μ (f n)))) · exact ((BFSSLocalL2.compactMul_continuous _ _ _).tendsto u |>.comp hf₁).prodMk_nhds (((cutoffGradient_continuous μ e χ).tendsto (u,v) |>.comp hf₂).prodMk_nhds ((BFSSLocalL2.compactMul_continuous _ _ _).tendsto u |>.comp hf₁)) · exact Eventually.of_forall (fun n => ⟨coreMul χ (f n),cutoff_core_tuple μ e w hw χ (f n)⟩) end end BFSSSliceSobolev namespace BFSSSliceSobolev noncomputable section open MeasureTheory Set Filter Topology variable {E F : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E] [FiniteDimensional ℝ E] [MeasurableSpace E] [BorelSpace E] [NormedAddCommGroup F] [InnerProductSpace ℝ F] [CompleteSpace F] variable (μ : Measure E) [IsFiniteMeasureOnCompacts μ] variable {ι : Type*} [Fintype ι] (e : ι → E) def bumpCore (φ : ContDiffBump (0 : E)) (h : ℝ) (hh : h ≠ 0) : Core (E := E) (F := ℝ) := ⟨fun x => φ (h • x),φ.contDiff.comp (contDiff_const.smul contDiff_id), φ.hasCompactSupport.comp_smul hh,by intro x hx; trivial⟩ omit [MeasurableSpace E] [BorelSpace E] in lemma bumpCore_apply (φ : ContDiffBump (0 : E)) (h : ℝ) (hh : h ≠ 0) (x : E) : bumpCore φ h hh x = φ (h • x) := rfl omit [MeasurableSpace E] [BorelSpace E] in lemma bumpCore_derivative (φ : ContDiffBump (0 : E)) (h : ℝ) (hh : h ≠ 0) (x a : E) : TestFunction.lineDerivCLM (k := ⊤) ℝ a (bumpCore φ h hh) x = fderiv ℝ (φ : E → ℝ) (h • x) (h • a) := by change fderiv ℝ (fun x => φ (h • x)) x a = _ have hs : HasFDerivAt (fun y : E => h • y) (h • ContinuousLinearMap.id ℝ E) x := (hasFDerivAt_id x).const_smul h have he := (((φ.contDiff : ContDiff ℝ 1 (φ : E → ℝ)).differentiable (by norm_num) (h • x)).hasFDerivAt.comp x hs).fderiv simpa only [Function.comp_def,ContinuousLinearMap.comp_apply,_root_.smul_apply,ContinuousLinearMap.id_apply,map_smul] using congrArg (fun L : E →L[ℝ] ℝ => L a) he omit [CompleteSpace F] [IsFiniteMeasureOnCompacts μ] in lemma scalarMul_bump_tendsto (φ : ContDiffBump (0 : E)) (h : ℕ → ℝ) (hh : ∀ n, h n ≠ 0) (ht : Tendsto h atTop (𝓝 0)) (u : Lp F 2 μ) : Tendsto (fun n => scalarMul μ (bumpCore φ (h n) (hh n)) u) atTop (𝓝 u) := by have hm (n : ℕ) : AEStronglyMeasurable (fun x : E => φ (h n • x)) μ := (φ.continuous.comp (continuous_const.smul continuous_id)).aestronglyMeasurable have hb (n : ℕ) : ∀ᵐ x ∂μ, |φ (h n • x)| ≤ 1 := ae_of_all μ (fun x => by rw [abs_of_nonneg φ.nonneg]; exact φ.le_one) have hl : ∀ᵐ x ∂μ, Tendsto (fun n => φ (h n • x)) atTop (𝓝 1) := by apply ae_of_all intro x have hhx : Tendsto (fun n => h n • x) atTop (𝓝 (0 : E)) := by simpa only [zero_smul] using ht.smul_const x have hφ0 : φ (0 : E) = 1 := φ.one_of_mem_closedBall (by simpa only [Metric.mem_closedBall,dist_self] using φ.rIn_pos.le) simpa only [hφ0,Function.comp_def] using φ.continuous.continuousAt.tendsto.comp hhx have he (n : ℕ) : scalarMul μ (bumpCore φ (h n) (hh n)) u = BFSSLocalL2.boundedMul (fun x => φ (h n • x)) (hm n) 1 (hb n) u := by apply Lp.ext filter_upwards [BFSSLocalL2.compactMul_ae _ _ _ u, BFSSLocalL2.boundedMul_ae _ (hm n) 1 (hb n) u] with x hx hy rw [hx,hy,bumpCore_apply] simpa only [he] using BFSSLocalL2.boundedMul_fixed_tendsto (fun n x => φ (h n • x)) hm 1 (by norm_num) hb hl u omit [CompleteSpace F] [IsFiniteMeasureOnCompacts μ] in lemma scalarMul_bump_derivative_tendsto (φ : ContDiffBump (0 : E)) (h : ℕ → ℝ) (hh : ∀ n, h n ≠ 0) (ht : Tendsto h atTop (𝓝 0)) (a : E) (u : Lp F 2 μ) : Tendsto (fun n => scalarMul μ (TestFunction.lineDerivCLM (k := ⊤) ℝ a (bumpCore φ (h n) (hh n))) u) atTop (𝓝 0) := by have hdc : Continuous (fderiv ℝ (φ : E → ℝ)) := (φ.contDiff : ContDiff ℝ 1 (φ : E → ℝ)).continuous_fderiv (by norm_num) obtain ⟨D,hD⟩ := (φ.hasCompactSupport.fderiv ℝ).exists_bound_of_continuous hdc have hD0 : 0 ≤ D := (norm_nonneg _).trans (hD 0) have hb (n : ℕ) : ‖scalarMul μ (TestFunction.lineDerivCLM (k := ⊤) ℝ a (bumpCore φ (h n) (hh n))) u‖ ≤ (D*|h n| *‖a‖)*‖u‖ := by apply BFSSLocalL2.norm_le_mul_of_ae_norm_le _ u (D*|h n| *‖a‖) (by positivity) filter_upwards [BFSSLocalL2.compactMul_ae _ _ _ u] with x hx rw [hx,norm_smul,bumpCore_derivative] apply mul_le_mul_of_nonneg_right _ (norm_nonneg _) calc _ ≤ ‖fderiv ℝ (φ : E → ℝ) (h n • x)‖*‖h n • a‖ := (fderiv ℝ (φ : E → ℝ) (h n • x)).le_opNorm _ _ ≤ D*‖h n • a‖ := mul_le_mul_of_nonneg_right (hD _) (norm_nonneg _) _ = D*|h n| *‖a‖ := by rw [norm_smul,Real.norm_eq_abs,mul_assoc] apply tendsto_zero_iff_norm_tendsto_zero.mpr apply squeeze_zero (fun n => norm_nonneg _) hb simpa only [abs_zero,mul_zero,zero_mul] using (ht.abs.const_mul D).mul_const ‖a‖ |>.mul_const ‖u‖ omit [CompleteSpace F] [IsFiniteMeasureOnCompacts μ] [Fintype ι] in lemma cutoffGradient_bump_tendsto (φ : ContDiffBump (0 : E)) (h : ℕ → ℝ) (hh : ∀ n, h n ≠ 0) (ht : Tendsto h atTop (𝓝 0)) (u : Lp F 2 μ) (v : Gradient (F := F) μ (ι := ι)) : Tendsto (fun n => cutoffGradient μ e (bumpCore φ (h n) (hh n)) u v) atTop (𝓝 v) := by have hp : Tendsto (fun n j => scalarMul μ (bumpCore φ (h n) (hh n)) (v j) + scalarMul μ (TestFunction.lineDerivCLM (k := ⊤) ℝ (e j) (bumpCore φ (h n) (hh n))) u) atTop (𝓝 (fun j => v j)) := by apply tendsto_pi_nhds.mpr intro j simpa only [add_zero] using (scalarMul_bump_tendsto μ φ h hh ht (v j)).add (scalarMul_bump_derivative_tendsto μ φ h hh ht (e j) u) exact (PiLp.continuous_toLp 2 _).tendsto (fun j => v j) |>.comp hp omit [FiniteDimensional ℝ E] [CompleteSpace F] [IsFiniteMeasureOnCompacts μ] in lemma cutoffMoment_eq_scalarMul (w : E → ℝ) (hw : Continuous w) (χ : Core (E := E) (F := ℝ)) (u : Lp F 2 μ) (hm : MemLp (fun x => w x • u x) 2 μ) : cutoffMoment μ w hw χ u = scalarMul μ χ (hm.toLp (fun x => w x • u x)) := by apply Lp.ext filter_upwards [BFSSLocalL2.compactMul_ae (fun x => w x*χ x) (hw.mul χ.continuous) χ.hasCompactSupport.mul_left u,BFSSLocalL2.compactMul_ae _ _ _ (hm.toLp (fun x => w x • u x)), hm.coeFn_toLp] with x hx hy hz change (BFSSLocalL2.compactMul (fun x => w x*χ x) (hw.mul χ.continuous) χ.hasCompactSupport.mul_left u : E → F) x = _ rw [hx,hy,hz,mul_comm,mul_smul] omit [CompleteSpace F] in theorem mem_weightedClosure (w : E → ℝ) (hw : Continuous w) {u : Lp F 2 μ} {v : Gradient (F := F) μ (ι := ι)} (hp : (u,v) ∈ closedGraph μ e) (hm : MemLp (fun x => w x • u x) 2 μ) : (u,v,hm.toLp (fun x => w x • u x)) ∈ weightedClosure μ e w hw := by let φ : ContDiffBump (0 : E) := ⟨1,2,by norm_num,by norm_num⟩ let h : ℕ → ℝ := fun n => 1/((n : ℝ)+1) have hh : ∀ n, h n ≠ 0 := fun n => ne_of_gt (by dsimp [h]; positivity) have ht : Tendsto h atTop (𝓝 0) := tendsto_one_div_add_atTop_nhds_zero_nat have h₁ := scalarMul_bump_tendsto μ φ h hh ht u have h₂ := cutoffGradient_bump_tendsto μ e φ h hh ht u v have h₃ : Tendsto (fun n => cutoffMoment μ w hw (bumpCore φ (h n) (hh n)) u) atTop (𝓝 (hm.toLp (fun x => w x • u x))) := by simp only [cutoffMoment_eq_scalarMul μ w hw _ u hm] exact scalarMul_bump_tendsto μ φ h hh ht _ exact isClosed_closure.mem_of_tendsto (h₁.prodMk_nhds (h₂.prodMk_nhds h₃)) (Eventually.of_forall fun n => cutoff_mem_weightedClosure μ e w hw (bumpCore φ (h n) (hh n)) hp) end end BFSSSliceSobolev namespace BFSSQuantum.AlgebraData noncomputable section open MeasureTheory Set Filter Topology variable {N : ℕ} (M : AlgebraData N) attribute [local irreducible] normalSlice gaugeAction coreToL2 local instance formClosureFermionNormedAddCommGroup : NormedAddCommGroup (Fermion N →L[ℝ] Fermion N) := inferInstance local instance formClosureFermionNormedSpace : NormedSpace ℝ (Fermion N →L[ℝ] Fermion N) := inferInstance def normalMomentWeight (q : Boson N) (x : M.NormalCoordinates q) : ℝ := Real.sqrt (M.normalQuadratic q (M.normalCoordinateIsometry q x : Boson N)) lemma normalMomentWeight_continuous (q : Boson N) : Continuous (M.normalMomentWeight q) := ((M.normalQuadratic_continuous q).comp ((continuous_subtype_val).comp (M.normalCoordinateIsometry q).continuous)).sqrt lemma normalWeightedCore_norm_sq (q : Boson N) (f : M.NormalCore q) : ‖BFSSSliceSobolev.weightedToL2 volume (M.normalMomentWeight q) (M.normalMomentWeight_continuous q) f‖^2 = ∫ x : M.NormalCoordinates q, M.normalQuadratic q (M.normalCoordinateIsometry q x : Boson N)* ‖(BFSSSliceSobolev.toL2 volume f) x‖^2 := by rw [BFSSLocalL2.lp_norm_sq] apply integral_congr_ae filter_upwards [BFSSSliceSobolev.weightedToL2_ae volume (M.normalMomentWeight q) (M.normalMomentWeight_continuous q) f,BFSSSliceSobolev.toL2_ae volume f] with x hw hf rw [hw,hf,norm_smul,Real.norm_eq_abs,mul_pow,sq_abs,normalMomentWeight, Real.sq_sqrt (M.normalQuadratic_nonneg q _)] theorem normalOscillator_nonneg (q : Boson N) (hq : q ∈ M.massiveZeros) (u : Lp (Fermion N) 2 (volume : Measure (M.NormalCoordinates q))) (v : M.NormalGradient q) (hd : M.NormalFormDomain q u v) : 0 ≤ M.normalOscillatorForm q u v := by let A := M.deformedFermionField 1 1 q let C : Set (Lp (Fermion N) 2 (volume : Measure (M.NormalCoordinates q)) × M.NormalGradient q × Lp (Fermion N) 2 (volume : Measure (M.NormalCoordinates q))) := {p | 0 ≤ (1/2 : ℝ)*‖p.2.1‖^2+‖p.2.2‖^2+inner ℝ p.1 (A.compLp p.1)} have hC : IsClosed C := by apply isClosed_le continuous_const exact ((continuous_const.mul (((continuous_fst.comp continuous_snd).norm).pow 2)).add (((continuous_snd.comp continuous_snd).norm).pow 2)).add (continuous_fst.inner ((A.compLpL 2 volume).continuous.comp continuous_fst)) have hs : Set.range (fun f : M.NormalCore q => (BFSSSliceSobolev.toL2 volume f, BFSSSliceSobolev.gradient volume (EuclideanSpace.basisFun (M.NormalIndex q) ℝ) f, BFSSSliceSobolev.weightedToL2 volume (M.normalMomentWeight q) (M.normalMomentWeight_continuous q) f)) ⊆ C := by rintro _ ⟨f,rfl⟩ have hf := M.normalOscillator_core_nonneg q hq f change 0 ≤ (1/2 : ℝ)*‖BFSSSliceSobolev.gradient volume (EuclideanSpace.basisFun (M.NormalIndex q) ℝ) f‖^2 + ‖BFSSSliceSobolev.weightedToL2 volume (M.normalMomentWeight q) (M.normalMomentWeight_continuous q) f‖^2 + inner ℝ (BFSSSliceSobolev.toL2 volume f) (A.compLp (BFSSSliceSobolev.toL2 volume f)) rw [M.normalWeightedCore_norm_sq] simpa only [normalOscillatorForm,BFSSNormalAnalysis.constant_quadratic_eq,A] using hf have hm := BFSSSliceSobolev.mem_weightedClosure volume (EuclideanSpace.basisFun (M.NormalIndex q) ℝ) (M.normalMomentWeight q) (M.normalMomentWeight_continuous q) hd.1 hd.2 have hc := closure_minimal hs hC hm change 0 ≤ (1/2 : ℝ)*‖v‖^2+‖hd.2.toLp (fun x => M.normalMomentWeight q x • u x)‖^2+ inner ℝ u (A.compLp u) at hc rw [normalOscillatorForm,←M.normalPotential_norm_sq q u hd.2, BFSSNormalAnalysis.constant_quadratic_eq] exact hc end end BFSSQuantum.AlgebraData end OAI