import OAI.Analysis.FactorGeneration.HaarPatches namespace OAI noncomputable section namespace Generator.Tracial /-! Extension of actual partial unitaries and ordered words from pH. The empty word maps to p, so word transport retains a final p. -/ section open UltrapowerBridge variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H] variable {M : VonNeumannAlgebra H} (p : AlgebraProjection M) def PartialUnitary.fromRepresentedCorner (v : PartialUnitary (representedCorner p)) : PartialUnitary M where support := ⟨cornerEmbedding p v.support.val,v.support.property.map (cornerEmbedding p)⟩ unitary := ⟨cornerEmbedding p v.val, by exact (congrArg (fun x => x * cornerEmbedding p v.val) (map_star (cornerEmbedding p) v.val).symm).trans ((map_mul (cornerEmbedding p) (star v.val) v.val).symm.trans (congrArg (cornerEmbedding p) v.unitary.initial)), by exact (congrArg (fun x => cornerEmbedding p v.val * x) (map_star (cornerEmbedding p) v.val).symm).trans ((map_mul (cornerEmbedding p) v.val (star v.val)).symm.trans (congrArg (cornerEmbedding p) v.unitary.final))⟩ theorem PartialUnitary.fromRepresentedCorner_support_le (v : PartialUnitary (representedCorner p)) : (v.fromRepresentedCorner p).support ≤ p := cornerEmbedding_left p v.support.val theorem cornerEmbedding_signedLetter (v : (representedCorner p).toStarSubalgebra) (s : Bool) : cornerEmbedding p (signedLetter v s)=signedLetter (cornerEmbedding p v) s := by cases s with | false => rfl | true => exact map_star (cornerEmbedding p) v theorem cornerEmbedding_patchingWord (v : (representedCorner p).toStarSubalgebra) (xs : List (Bool × (representedCorner p).toStarSubalgebra)) : cornerEmbedding p (patchingWord v xs)= patchingWord (cornerEmbedding p v) (xs.map (fun a => (a.1,cornerEmbedding p a.2)))*p.val := by induction xs with | nil => simp [patchingWord] | cons a xs ih => simp only [patchingWord,List.map_cons,map_mul,cornerEmbedding_signedLetter,ih,mul_assoc] theorem cornerEmbedding_patchingWord_nonempty (v : (representedCorner p).toStarSubalgebra) (xs : List (Bool × (representedCorner p).toStarSubalgebra)) (hx : xs ≠ []) : cornerEmbedding p (patchingWord v xs)= patchingWord (cornerEmbedding p v) (xs.map (fun a => (a.1,cornerEmbedding p a.2))) := by induction xs with | nil => exact (hx rfl).elim | cons a xs ih => cases xs with | nil => simp [patchingWord,cornerEmbedding_signedLetter] | cons b ys => change cornerEmbedding p (signedLetter v a.1*a.2*patchingWord v (b::ys)) = signedLetter (cornerEmbedding p v) a.1*cornerEmbedding p a.2* patchingWord (cornerEmbedding p v) ((b::ys).map (fun c => (c.1,cornerEmbedding p c.2))) exact (map_mul (cornerEmbedding p) (signedLetter v a.1 * a.2) (patchingWord v (b :: ys))).trans (congrArg₂ (fun x y : M.toStarSubalgebra => x * y) ((map_mul (cornerEmbedding p) (signedLetter v a.1) a.2).trans (congrArg (fun x => x * cornerEmbedding p a.2) (cornerEmbedding_signedLetter p v a.1))) (ih (by simp))) theorem cornerEmbedding_trace (τ : TracialRepresentation M) (hp : p.val ≠ 0) (a : (representedCorner p).toStarSubalgebra) : τ.trace (cornerEmbedding p a)=τ.trace p.val*(representedCornerTrace τ p hp).trace a := by rw [representedCornerTrace_trace] have ht : τ.trace p.val ≠ 0 := by intro h have := projection_trace_pos τ p.val p.property hp simp [h] at this exact (mul_div_cancel₀ _ ht).symm theorem cornerEmbedding_trace_re (τ : TracialRepresentation M) (hp : p.val ≠ 0) (a : (representedCorner p).toStarSubalgebra) : (τ.trace (cornerEmbedding p a)).re= (τ.trace p.val).re*((representedCornerTrace τ p hp).trace a).re := by rw [cornerEmbedding_trace p τ hp,projection_trace_real τ p,Complex.mul_re] simp end /-! Finite partial independence in every nonzero represented subcorner, with actual ambient support, membership and trace estimates. -/ section open UltrapowerBridge variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H] variable {N M : VonNeumannAlgebra H} (τ : TracialRepresentation M) variable (hNM : N ≤ M) variable (hfactor : ∀ c : N.toStarSubalgebra, (∀ a : N.toStarSubalgebra,a*c=c*a) → ∃ z : ℂ,c=z • (1 : N.toStarSubalgebra)) variable (hdiff : ∀ r : N.toStarSubalgebra,IsStarProjection r → r ≠ 0 → ∃ q : N.toStarSubalgebra,IsStarProjection q ∧ q ≠ 0 ∧ q ≠ r ∧ r*q=q ∧ q*r=q) variable (hirr : ∀ c : M.toStarSubalgebra, (∀ a : N.toStarSubalgebra,coordinateInclusion hNM a*c=c*coordinateInclusion hNM a) → ∃ z : ℂ,c=z • (1 : M.toStarSubalgebra)) variable (hsep : TopologicalSpace.IsSeparable (Set.range (baseVector τ))) include hfactor hdiff hirr hsep theorem exists_represented_corner_partial_independence (p : AlgebraProjection M) (hpN : p.val.val ∈ N) (hp : p.val ≠ 0) (F : Finset (representedCorner p).toStarSubalgebra) (hF : ∀ x ∈ F,‖x‖ ≤ 1) (hc : ∀ x ∈ F,τ.trace (cornerEmbedding p x)=0) (n : ℕ) (ε : ℝ) (hε : 0 < ε) : ∃ v : PartialUnitary M,v.val.val ∈ N ∧ v.support ≤ p ∧ (τ.trace p.val).re/4 < (τ.trace v.support.val).re ∧ ∀ x₀ ∈ (F : Set (representedCorner p).toStarSubalgebra) ∪ {1}, ∀ xs : List (Bool × (representedCorner p).toStarSubalgebra), 1 ≤ xs.length → xs.length ≤ n → patchingCoefficients (F : Set (representedCorner p).toStarSubalgebra) xs → ‖τ.trace (cornerEmbedding p x₀ * patchingWord v.val (xs.map (fun a => (a.1,cornerEmbedding p a.2))))‖ ≤ (τ.trace p.val).re*ε := by let σ := representedCornerTrace τ p hp have hf := representedCorner_factor (restrictedTrace τ hNM) (projectionInSubalgebra p hpN) hfactor have hd := representedCorner_diffuse (projectionInSubalgebra p hpN) hdiff have hi := representedCorner_irreducible τ p hpN hNM hirr have hs := representedCorner_separable τ p hp hsep have hcenter : ∀ x ∈ F,σ.trace x=0 := by intro x hx rw [representedCornerTrace_trace,hc x hx,zero_div] obtain ⟨u,hu,ht,hw⟩ := exists_finite_partial_independence σ (representedSubcorner_le p hpN hNM) hf hd hi hs F hF hcenter n ε hε refine ⟨u.fromRepresentedCorner p,hu,u.fromRepresentedCorner_support_le p,?_,?_⟩ · change (τ.trace p.val).re/4 < (τ.trace (cornerEmbedding p u.support.val)).re rw [cornerEmbedding_trace_re p τ hp] have hpos := projection_trace_pos τ p.val p.property hp have h := mul_lt_mul_of_pos_left ht hpos dsimp [σ] at h linarith · intro x₀ hx₀ xs hlen hn hcoeff have hne : xs ≠ [] := by intro h; simp [h] at hlen have he : cornerEmbedding p x₀ * patchingWord (u.fromRepresentedCorner p).val (xs.map (fun a => (a.1,cornerEmbedding p a.2))) = cornerEmbedding p (x₀*patchingWord u.val xs) := by rw [map_mul,cornerEmbedding_patchingWord_nonempty p _ _ hne] rfl rw [he,cornerEmbedding_trace p τ hp,norm_mul,projection_trace_real τ p, Complex.norm_real,Real.norm_of_nonneg ((projection_trace_pos τ p.val p.property hp).le)] exact mul_le_mul_of_nonneg_left (hw x₀ hx₀ xs hlen hn hcoeff) ((projection_trace_pos τ p.val p.property hp).le) end /-! Ordered-word transport with ambient unit endpoints, and contractive compression of supported centered coefficients. -/ section open UltrapowerBridge variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H] variable {M : VonNeumannAlgebra H} (p : AlgebraProjection M) theorem cornerCompress_norm_le (a : M.toStarSubalgebra) : ‖cornerCompress p a‖ ≤ ‖a‖ := by apply ContinuousLinearMap.opNorm_le_bound _ (norm_nonneg _) intro y change ‖p.val.val (a.val y.val)‖ ≤ ‖a‖*‖y‖ exact ((p.val.val.le_opNorm _).trans (mul_le_of_le_one_left (norm_nonneg _) p.property.norm_le)).trans (a.val.le_opNorm y.val) theorem cornerCompress_supported (a : M.toStarSubalgebra) (hl : p.val*a=a) (hr : a*p.val=a) : cornerEmbedding p (cornerCompress p a)=a := by rw [cornerEmbedding_compress,hl,hr] theorem cornerEmbedding_ordered_tail (v : (representedCorner p).toStarSubalgebra) (x : ℕ → (representedCorner p).toStarSubalgebra) (xs : List (Bool × ℕ)) (s : Bool) (last : Option ℕ) : cornerEmbedding p (patchingWord v (xs.map (fun a => (a.1,x a.2)) ++ [(s,optionalCoefficient x last)]))= patchingWord (cornerEmbedding p v) (xs.map (fun a => (a.1,cornerEmbedding p (x a.2))) ++ [(s,optionalCoefficient (fun i => cornerEmbedding p (x i)) last)]) := by induction xs with | nil => cases last <;> simp only [List.map_nil,List.nil_append,patchingWord,mul_one,optionalCoefficient, map_mul,← cornerEmbedding_signedLetter] | cons a xs ih => change cornerEmbedding p (signedLetter v a.1*x a.2*patchingWord v (xs.map (fun b => (b.1,x b.2)) ++ [(s,optionalCoefficient x last)])) = _ exact (map_mul (cornerEmbedding p) (signedLetter v a.1 * x a.2) _).trans (congrArg₂ (fun y z : M.toStarSubalgebra => y * z) ((map_mul (cornerEmbedding p) (signedLetter v a.1) (x a.2)).trans (congrArg (fun y => y * cornerEmbedding p (x a.2)) (cornerEmbedding_signedLetter p v a.1))) ih) theorem cornerEmbedding_ordered_moment (v : (representedCorner p).toStarSubalgebra) (x : ℕ → (representedCorner p).toStarSubalgebra) (first last : Option ℕ) (xs : List (Bool × ℕ)) (s : Bool) : cornerEmbedding p (optionalCoefficient x first * patchingWord v (xs.map (fun a => (a.1,x a.2)) ++ [(s,optionalCoefficient x last)]))= optionalCoefficient (fun i => cornerEmbedding p (x i)) first * patchingWord (cornerEmbedding p v) (xs.map (fun a => (a.1,cornerEmbedding p (x a.2))) ++ [(s,optionalCoefficient (fun i => cornerEmbedding p (x i)) last)]) := by cases first with | none => simpa only [optionalCoefficient,one_mul] using cornerEmbedding_ordered_tail p v x xs s last | some i => rw [map_mul,cornerEmbedding_ordered_tail] rfl end /-! Diagonal partial independence in genuinely varying Hilbert-space corners. The result retains an actual ambient partial-unitary sequence. -/ open Filter open scoped Topology section open UltrapowerBridge variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H] variable {N M : VonNeumannAlgebra H} (τ : TracialRepresentation M) variable (hNM : N ≤ M) variable (hfactor : ∀ c : N.toStarSubalgebra, (∀ a : N.toStarSubalgebra,a*c=c*a) → ∃ z : ℂ,c=z • (1 : N.toStarSubalgebra)) variable (hdiff : ∀ r : N.toStarSubalgebra,IsStarProjection r → r ≠ 0 → ∃ q : N.toStarSubalgebra,IsStarProjection q ∧ q ≠ 0 ∧ q ≠ r ∧ r*q=q ∧ q*r=q) variable (hirr : ∀ c : M.toStarSubalgebra, (∀ a : N.toStarSubalgebra,coordinateInclusion hNM a*c=c*coordinateInclusion hNM a) → ∃ z : ℂ,c=z • (1 : M.toStarSubalgebra)) variable (hsep : TopologicalSpace.IsSeparable (Set.range (baseVector τ))) include hfactor hdiff hirr hsep theorem exists_varying_corner_partial_independence (p : ℕ → AlgebraProjection M) (hpN : ∀ j,(p j).val.val ∈ N) (hp : ∀ j,(p j).val ≠ 0) (x : (j : ℕ) → ℕ → (representedCorner (p j)).toStarSubalgebra) (hx : ∀ j i,‖x j i‖ ≤ 1) (hc : ∀ j i,τ.trace (cornerEmbedding (p j) (x j i))=0) : ∃ v : ℕ → PartialUnitary M, (∀ j,(v j).val.val ∈ N) ∧ (∀ j,(v j).support ≤ p j) ∧ (∀ j,(τ.trace (p j).val).re/4 < (τ.trace (v j).support.val).re) ∧ ∀ first last : Option ℕ,∀ xs : List (Bool × ℕ),∀ s : Bool, Tendsto (fun j => τ.trace ( optionalCoefficient (fun i => cornerEmbedding (p j) (x j i)) first * patchingWord (v j).val (xs.map (fun a => (a.1,cornerEmbedding (p j) (x j a.2))) ++ [(s,optionalCoefficient (fun i => cornerEmbedding (p j) (x j i)) last)]))) atTop (𝓝 0) := by classical let σ := fun j => representedCornerTrace τ (p j) (hp j) let F := fun j => (Finset.range (j+1)).image (x j) have hstage (j : ℕ) := exists_finite_partial_independence (σ j) (representedSubcorner_le (p j) (hpN j) hNM) (representedCorner_factor (restrictedTrace τ hNM) (projectionInSubalgebra (p j) (hpN j)) hfactor) (representedCorner_diffuse (projectionInSubalgebra (p j) (hpN j)) hdiff) (representedCorner_irreducible τ (p j) (hpN j) hNM hirr) (representedCorner_separable τ (p j) (hp j) hsep) (F j) (by intro a ha obtain ⟨i,_,rfl⟩ := Finset.mem_image.mp ha exact hx j i) (by intro a ha obtain ⟨i,_,rfl⟩ := Finset.mem_image.mp ha rw [representedCornerTrace_trace,hc j i,zero_div]) (j+1) (1/((j : ℝ)+1)) (by positivity) choose u hu ht hw using hstage let v := fun j => (u j).fromRepresentedCorner (p j) refine ⟨v,hu,fun j => (u j).fromRepresentedCorner_support_le (p j),?_,?_⟩ · intro j change (τ.trace (p j).val).re/4 < (τ.trace (cornerEmbedding (p j) (u j).support.val)).re rw [cornerEmbedding_trace_re (p j) τ (hp j)] have h := mul_lt_mul_of_pos_left (ht j) (projection_trace_pos τ (p j).val (p j).property (hp j)) dsimp [σ] at h linarith · intro first last xs s apply tendsto_iff_norm_sub_tendsto_zero.mpr simp only [sub_zero] apply squeeze_zero' (Eventually.of_forall (fun _ => norm_nonneg _)) ?_ tendsto_one_div_add_atTop_nhds_zero_nat have hopt (i : Option ℕ) : ∀ᶠ j : ℕ in atTop, optionalCoefficient (x j) i ∈ (F j : Set _) ∪ {1} := by cases i with | none => exact Eventually.of_forall (fun _ => Or.inr rfl) | some i => filter_upwards [eventually_ge_atTop i] with j hj exact Or.inl (Finset.mem_image.mpr ⟨i,Finset.mem_range.mpr (by omega),rfl⟩) filter_upwards [eventually_list_indices (xs.map Prod.snd),eventually_ge_atTop xs.length, hopt first,hopt last] with j hj hlen hfirst hlast have he := cornerEmbedding_ordered_moment (p j) (u j).val (x j) first last xs s change ‖τ.trace (optionalCoefficient (fun i => cornerEmbedding (p j) (x j i)) first * patchingWord (cornerEmbedding (p j) (u j).val) _)‖ ≤ _ rw [← he,cornerEmbedding_trace (p j) τ (hp j),norm_mul] have hb : ‖(σ j).trace (optionalCoefficient (x j) first * patchingWord (u j).val (xs.map (fun a => (a.1,x j a.2)) ++ [(s,optionalCoefficient (x j) last)]))‖ ≤ 1/((j : ℝ)+1) := by apply hw j _ hfirst _ (by simp) (by simpa using Nat.add_le_add_right hlen 1) apply patchingCoefficients_append_endpoint _ _ ?_ (s,optionalCoefficient (x j) last) hlast intro a ha obtain ⟨b,hb,rfl⟩ := List.mem_map.mp ha exact Finset.mem_image.mpr ⟨b.2,Finset.mem_range.mpr (by have hh := hj b.2 (List.mem_map.mpr ⟨b,hb,rfl⟩) omega),rfl⟩ have htrace : ‖τ.trace (p j).val‖ ≤ 1 := ((τ.norm_trace_le_norm₂ _).trans (τ.norm₂_le_norm _)).trans (p j).property.norm_le exact (mul_le_of_le_one_left (norm_nonneg _) htrace).trans hb end /-! Actual coordinate partial-unitary witnesses in supported corners, followed by exact quotient moments and the ambient quarter-support bound. -/ open Filter open scoped Topology open UltrapowerBridge variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H] variable {N M : VonNeumannAlgebra H} (τ : TracialRepresentation M) variable (hNM : N ≤ M) variable (hfactor : ∀ c : N.toStarSubalgebra, (∀ a : N.toStarSubalgebra,a*c=c*a) → ∃ z : ℂ,c=z • (1 : N.toStarSubalgebra)) variable (hdiff : ∀ r : N.toStarSubalgebra,IsStarProjection r → r ≠ 0 → ∃ q : N.toStarSubalgebra,IsStarProjection q ∧ q ≠ 0 ∧ q ≠ r ∧ r*q=q ∧ q*r=q) variable (hirr : ∀ c : M.toStarSubalgebra, (∀ a : N.toStarSubalgebra,coordinateInclusion hNM a*c=c*coordinateInclusion hNM a) → ∃ z : ℂ,c=z • (1 : M.toStarSubalgebra)) variable (hsep : TopologicalSpace.IsSeparable (Set.range (baseVector τ))) include hfactor hdiff hirr hsep theorem exists_supported_corner_partial_sequence (p : ℕ → AlgebraProjection M) (hpN : ∀ j,(p j).val.val ∈ N) (hp : ∀ j,(p j).val ≠ 0) (x : ℕ → ℕ → M.toStarSubalgebra) (hx : ∀ i j,‖x i j‖ ≤ 1) (hc : ∀ i j,τ.trace (x i j)=0) (hl : ∀ i j,(p j).val*x i j=x i j) (hr : ∀ i j,x i j*(p j).val=x i j) : ∃ v : ℕ → PartialUnitary M, (∀ j,(v j).val.val ∈ N) ∧ (∀ j,(v j).support ≤ p j) ∧ (∀ j,(τ.trace (p j).val).re/4 < (τ.trace (v j).support.val).re) ∧ ∀ first last : Option ℕ,∀ xs : List (Bool × ℕ),∀ s : Bool, Tendsto (fun j => τ.trace (indexedCoefficient x j first * patchingWord (v j).val (xs.map (fun a => (a.1,x a.2 j)) ++ [(s,indexedCoefficient x j last)]))) atTop (𝓝 0) := by let y := fun j i => cornerCompress (p j) (x i j) have he (j i : ℕ) : cornerEmbedding (p j) (y j i)=x i j := cornerCompress_supported (p j) (x i j) (hl i j) (hr i j) obtain ⟨v,hv,hs,ht,hw⟩ := exists_varying_corner_partial_independence τ hNM hfactor hdiff hirr hsep p hpN hp y (fun j i => (cornerCompress_norm_le (p j) (x i j)).trans (hx i j)) (fun j i => by rw [he]; exact hc i j) refine ⟨v,hv,hs,ht,?_⟩ intro first last xs s have hh := hw first last xs s cases first <;> cases last <;> simpa only [he,optionalCoefficient,indexedCoefficient] using hh theorem exists_quotient_corner_partial_sequence (ω : Ultrafilter ℕ) (hω : (ω : Filter ℕ) ≤ atTop) (g : Bounded M) (hg : ∀ j,IsStarProjection (g.val j)) (hgN : ∀ j,(g.val j).val ∈ N) (hg0 : ∀ j,g.val j ≠ 0) (x : ℕ → Bounded M) (hx : ∀ i j,‖(x i).val j‖ ≤ 1) (hc : ∀ i j,τ.trace ((x i).val j)=0) (hl : ∀ i,g*x i=x i) (hr : ∀ i,x i*g=x i) : ∃ v : ℕ → PartialUnitary M, (∀ j,(v j).val.val ∈ N) ∧ (∀ j,g.val j*(v j).support.val=(v j).support.val) ∧ (quotientTrace τ ω (quotientMap τ (ω : Filter ℕ) g)).re/4 ≤ (quotientTrace τ ω (quotientMap τ (ω : Filter ℕ) (boundedPartialSupport v))).re ∧ ∀ first last : Option ℕ,∀ xs : List (Bool × ℕ),∀ s : Bool, quotientTrace τ ω (optionalCoefficient (fun i => quotientMap τ (ω : Filter ℕ) (x i)) first * algebraPatchingWord (quotientMap τ (ω : Filter ℕ) (boundedPartialUnitary v)) (xs.map (fun a => (a.1,quotientMap τ (ω : Filter ℕ) (x a.2))) ++ [(s,optionalCoefficient (fun i => quotientMap τ (ω : Filter ℕ) (x i)) last)]))=0 := by let p := fun j => (⟨g.val j,hg j⟩ : AlgebraProjection M) obtain ⟨v,hv,hs,ht,hw⟩ := exists_supported_corner_partial_sequence τ hNM hfactor hdiff hirr hsep p hgN hg0 (fun i => (x i).val) hx hc (fun i j => congrArg (fun a : Bounded M => a.val j) (hl i)) (fun i j => congrArg (fun a : Bounded M => a.val j) (hr i)) refine ⟨v,hv,hs,?_,?_⟩ · apply le_of_tendsto_of_tendsto ((Complex.continuous_re.continuousAt.tendsto.comp (traceRep_tendsto τ ω g)).div_const 4) (Complex.continuous_re.continuousAt.tendsto.comp (traceRep_tendsto τ ω (boundedPartialSupport v))) exact Eventually.of_forall (fun j => (ht j).le) · intro first last xs s exact quotient_ordered_moment_zero τ ω hω v x first last xs s (hw first last xs s) end Generator.Tracial end end OAI