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Proof of The Half-Relaxed Limits of the Regularised N-Particle Dyson Solutions are Viscosity Sub- and Supersolutions of the Limit Dyson Equation up to a Cost Defect

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· 21,351 chars · 28 deps · depth 49 Reason: Proof that the half-relaxed limits are viscosity sub- and supersolutions of the limit Dyson equation up to the cost defect.

At a test point, Gibbs maximisers of the regularised particle solutions tilted by the block test function concentrate at the limit measure; integrating the semiconvex particle sub/supersolution against them and passing to the limit with the particle score limit yields the tested inequality at the point itself, up to the cost defect htauh_tau.

Proof

Each result cited is universally quantified over the data in its own statement, and is applied to the data named here. Throughout, N0N_{0}, ε0\varepsilon_{0}, C0C_{0}, e∗e_{*}, p0,Np_{0,N}, rNr_{N}, θ1,N\theta_{1,N}, θ2,N\theta_{2,N}, gN±g^{\pm}_{N}, w‾N,τ\overline{w}_{N,\tau} and w‾N,τ\underline{w}_{N,\tau} are those of Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy, and e0e_{0}, the block test functions χN±\chi^{\pm}_{N}, the sets DN\mathcal{D}_{N}, DNΣ\mathcal{D}^{\Sigma}_{N} and the relative scores ΣN\Sigma_{N} are those of Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity. For a function ff on WNW_{N}, fˉ\bar{f} denotes its extension by 00 to RN\mathbb{R}^{N}. Every law Q∈DNQ\in\mathcal{D}_{N} satisfies Q(WN)=1Q(W_{N})=1 (The Relative Free Energy and the Relative Score of a Probability Measure for a Potential on an Open Set §energy), so integrals against it may be computed on WNW_{N}.

Step 0 (clause 1). Each set whose least upper bound defines ωg(s)\omega_{g}(s) consists of nonnegative numbers and is bounded above by 2bg2b_{g}, so 0≤ωg(s)≤2bg0\le\omega_{g}(s)\le2b_{g} for s≥0s\ge0; in particular 0≤hτ≤2bg0\le h_{\tau}\le2b_{g}. Let ε>0\varepsilon>0. If bg=0b_{g}=0 then ωg=0\omega_{g}=0, so hτ=0h_{\tau}=0 for every τ\tau, and τ0=1\tau_{0}=1 serves. Otherwise, gg being uniformly continuous (The N-Particle Dyson Game and its Mean-Field Limit: Standing Data and Equations §data, Uniformly Continuous Map Between Metric Spaces), there is sε>0s_{\varepsilon}>0 with ∣g(μ)−g(ν)∣<ε|g(\mu)-g(\nu)|<\varepsilon whenever W2(μ,ν)<sεW_{2}(\mu,\nu)<s_{\varepsilon}; hence every element of the set defining ωg(s)\omega_{g}(s) is less than ε\varepsilon when 0≤s≤sε/20\le s\le s_{\varepsilon}/2, and ωg(s)≤ε\omega_{g}(s)\le\varepsilon for such ss. Put τ0=λsε2/(32bg)\tau_{0}=\lambda s_{\varepsilon}^{2}/(32b_{g}). For 0<τ≤τ00<\tau\le\tau_{0}, 2Rτ=(8τλ−1bg)1/2≤(8τ0λ−1bg)1/2=sε/2\sqrt{2}R_{\tau}=(8\tau\lambda^{-1}b_{g})^{1/2}\le(8\tau_{0}\lambda^{-1}b_{g})^{1/2}=s_{\varepsilon}/2, and ωg\omega_{g} is nondecreasing, so hτ≤εh_{\tau}\le\varepsilon.

Clause 2: data and order of choice. Fix τ>0\tau>0 and write uˉ=uˉτ\bar{u}=\bar{u}_{\tau} and w‾N=w‾N,τ\overline{w}_{N}=\overline{w}_{N,\tau}. Following Viscosity Subsolution, Supersolution and Solution of a Second-Order Equation on the Wasserstein Space §subsolution, fix δ\delta with 0<δ<10<\delta<1, an intrinsic test function φ\varphi on D\mathcal{D}, a point μ^∈D\hat{\mu}\in\mathcal{D} at which uˉδ−−φ\bar{u}^{-}_{\delta}-\varphi has a local maximum relative to D\mathcal{D}, with a radius ρ>0\rho>0 as in Local Maximum of a Function Relative to a Subset of a Metric Space, and ε>0\varepsilon>0. Put q=∇φ(μ^)q=\nabla\varphi(\hat{\mu}). The choices are then made in this order: the radii θ(η)\theta(\eta) (Step 2); the realising levels (Nk)k(N_{k})_{k}, then for each jj the numbers ηj,rj,Kj\eta_{j},r_{j},K_{j}, the index kjk_{j} and the law QjQ_{j} (Step 3); the recovery points xkx^{k} (Step 6); the witnesses (Step 8).

Step 1 (the envelope is exact). By Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §modulus, applied in both orders, ∣uˉ(μ)−uˉ(μ′)∣≤12τW(3W+2Rτ)|\bar{u}(\mu)-\bar{u}(\mu')|\le\frac{1}{2\tau}W(3W+2R_{\tau}) with W=W2(μ,μ′)W=W_{2}(\mu,\mu'), for μ,μ′∈D\mu,\mu'\in\mathcal{D}; so uˉ\bar{u} is continuous on D\mathcal{D}. E\mathcal{E} is lower semicontinuous on D\mathcal{D} by The Confined Logarithmic-Energy Pair is a Displacement Convex, Wasserstein-Coercive Penalty Pair with Closed Score and Regular Penalised Maxima §growth, and uˉ\bar{u} has penalty-subordinate growth from above, as recorded in the statement. By Basic Properties of the Delta-Envelopes on the Wasserstein Space §exact, uˉδ−(ν)=uˉ(ν)−δE(ν)\bar{u}^{-}_{\delta}(\nu)=\bar{u}(\nu)-\delta\mathcal{E}(\nu) for every ν∈D\nu\in\mathcal{D}, so for every ν∈D\nu\in\mathcal{D} with W2(ν,μ^)<ρW_{2}(\nu,\hat{\mu})<\rho

uˉ(ν)−δE(ν)−φ(ν)≤uˉ(μ^)−δE(μ^)−φ(μ^).(1)\bar{u}(\nu)-\delta\mathcal{E}(\nu)-\varphi(\nu)\le\bar{u}(\hat{\mu})-\delta\mathcal{E}(\hat{\mu})-\varphi(\hat{\mu}).\tag{1}

Step 2 (the local linear bound). By property (b) of Intrinsic Test Functions on the Wasserstein Space and Their Translation Hessians §test, φ\varphi is differentiable along couplings at μ^∈D\hat{\mu}\in\mathcal{D} in the sense of The Intrinsic Calculus on the Wasserstein Space: Standing Notation §gradients, and q∈Tμ^⊆L2(μ^;R)q\in T_{\hat{\mu}}\subseteq L^{2}(\hat{\mu};\mathbb{R}). For η>0\eta>0 let θ(η)>0\theta(\eta)>0 be as in Differentiability of a Function on the Wasserstein Space Along Couplings, and Its Gradient §differentiable at μ^\hat{\mu} with gradient qq and with η\eta in place of its ε\varepsilon. Let ν∈D\nu\in\mathcal{D} with W2(ν,μ^)<min⁡(ρ,θ(η))W_{2}(\nu,\hat{\mu})<\min(\rho,\theta(\eta)) and let TT be an optimal map from μ^\hat{\mu} to ν\nu. As recorded in the statement of Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity, the class of TT lies in L2(μ^;R)L^{2}(\hat{\mu};\mathbb{R}) and ∥T−id∥μ^=W2(ν,μ^)\lVert T-\mathrm{id}\rVert_{\hat{\mu}}=W_{2}(\nu,\hat{\mu}); so The Displacement Pairing of a Square-Integrable Vector Field Along a Coupling §displacement with S=TS=T gives πT=(id,T)#μ^∈Π(μ^,ν)\pi_{T}=(\mathrm{id},T)_{\#}\hat{\mu}\in\Pi(\hat{\mu},\nu) with I(πT)=W2(ν,μ^)2<θ(η)2I(\pi_{T})=W_{2}(\nu,\hat{\mu})^{2}<\theta(\eta)^{2} and J(q,πT)=⟨q,T−id⟩μ^\mathcal{J}(q,\pi_{T})=\langle q,T-\mathrm{id}\rangle_{\hat{\mu}}. Hence φ(ν)−φ(μ^)≤⟨q,T−id⟩μ^+ηW2(ν,μ^)\varphi(\nu)-\varphi(\hat{\mu})\le\langle q,T-\mathrm{id}\rangle_{\hat{\mu}}+\eta W_{2}(\nu,\hat{\mu}), and with (1)

uˉ(ν)−δE(ν)≤uˉ(μ^)−δE(μ^)+⟨q,T−id⟩μ^+η W2(ν,μ^).(2)\bar{u}(\nu)-\delta\mathcal{E}(\nu)\le\bar{u}(\hat{\mu})-\delta\mathcal{E}(\hat{\mu})+\langle q,T-\mathrm{id}\rangle_{\hat{\mu}}+\eta\,W_{2}(\nu,\hat{\mu}).\tag{2}

This is the hypothesis of Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub with η′=η\eta'=\eta and r0=min⁡(ρ,θ(η))r_{0}=\min(\rho,\theta(\eta)).

Step 3 (diagonal choice of Gibbs laws). Fix realising levels (Nk)k(N_{k})_{k} for uˉ\bar{u} at μ^\hat{\mu} (Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §realising). For j∈Nj\in\mathbb{N} put ηj=1/j\eta_{j}=1/j, rj=min⁡(ρ,θ(1/j))r_{j}=\min(\rho,\theta(1/j)) and

Kj=max⁡(j, 2(2λ−1bg+∣e0∣+∣E(μ^)∣+∥q∥μ^2)rj−2),K_{j}=\max\Bigl(j,\ 2\bigl(2\lambda^{-1}b_{g}+|e_{0}|+|\mathcal{E}(\hat{\mu})|+\lVert q\rVert_{\hat{\mu}}^{2}\bigr)r_{j}^{-2}\Bigr),

so that (τ,δ,μ^,q,ηj,rj,Kj)(\tau,\delta,\hat{\mu},q,\eta_{j},r_{j},K_{j}) are admissible data of Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity and, by Step 2, clause Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub applies; let (πk(j))k(\pi^{(j)}_{k})_{k} be its Gibbs laws. By Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub-energy and Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub-concentration, the latter with 1/(jKj)1/(jK_{j}) in place of its ε\varepsilon, there is k0(j)k_{0}(j) such that both conclusions hold for k≥k0(j)k\ge k_{0}(j). Choose recursively kj≥k0(j)k_{j}\ge k_{0}(j) with kj>kj−1k_{j}>k_{j-1}, and put Mj=NkjM_{j}=N_{k_{j}}, strictly increasing with M1≥N0≥2M_{1}\ge N_{0}\ge2, and Qj=πkj(j)Q_{j}=\pi^{(j)}_{k_{j}}, which lies in DMjΣ\mathcal{D}^{\Sigma}_{M_{j}} by Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub-score. Write W(x)=W2(μxMj,μ^)W(x)=W_{2}(\mu^{M_{j}}_{x},\hat{\mu}). Since Kj≥j≥1K_{j}\ge j\ge1,

Kj2∫W2 dQj≤2j2+1j,∫W2 dQj≤1j2(2j2+1j),(3)K_{j}^{2}\int W^{2}\,dQ_{j}\le\frac{2}{j^{2}}+\frac{1}{j},\qquad\int W^{2}\,dQ_{j}\le\frac{1}{j^{2}}\Bigl(\frac{2}{j^{2}}+\frac{1}{j}\Bigr),\tag{3}

both tending to 00; with E1E_{1} as in Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub-energy, which does not depend on jj,

∫PMjMj dQj≤E1,αj:=1Mj∥ΣMj(Qj)∥Qj2≤A∗:=2δ2(2∥q∥μ^2+24+4τ(λ−1bg+E1+∣e∗∣)).(4)\int\frac{P_{M_{j}}}{M_{j}}\,dQ_{j}\le E_{1},\qquad\alpha_{j}:=\frac{1}{M_{j}}\lVert\Sigma_{M_{j}}(Q_{j})\rVert_{Q_{j}}^{2}\le A_{*}:=\frac{2}{\delta^{2}}\Bigl(2\lVert q\rVert_{\hat{\mu}}^{2}+24+\frac{4}{\tau}\bigl(\lambda^{-1}b_{g}+E_{1}+|e_{*}|\bigr)\Bigr).\tag{4}

By The Discrete Dyson Energy per Particle: Bounds, Compactness with a Lower Limit, and Recovery Configurations with Separated Particles §bounds, p0,N≥e∗Np_{0,N}\ge e_{*}N, so (4) gives

0≤∫PMj−p0,MjMj2 dQj≤E1+∣e∗∣Mj.(5)0\le\int\frac{P_{M_{j}}-p_{0,M_{j}}}{M_{j}^{2}}\,dQ_{j}\le\frac{E_{1}+|e_{*}|}{M_{j}}.\tag{5}

Step 4 (limits of the score terms). Let Gj=Mj∇χMj+G_{j}=M_{j}\nabla\chi^{+}_{M_{j}}, χMj+\chi^{+}_{M_{j}} having data (q,Kj)(q,K_{j}); by Quantile Blocks of an Atomless Measure on the Line: Block Maps, Distances to Ordered Empirical Measures, and the Block Test Function §test-function its ii-th component is qˉi+2Kj(xi−mi)\bar{q}_{i}+2K_{j}(x_{i}-m_{i}), an affine function of xx, so Gj∈L2(Qj;RMj)G_{j}\in L^{2}(Q_{j};\mathbb{R}^{M_{j}}). By (3) and (4), The Mean-Field Limit of the Relative Score of Laws of Dyson Particles Concentrating at a Measure applies to (Mj)j(M_{j})_{j}, (Qj)j(Q_{j})_{j}, μ^\hat{\mu} and A∗A_{*}; by The Mean-Field Limit of the Relative Score of Laws of Dyson Particles Concentrating at a Measure §domain, μ^∈DΣ\hat{\mu}\in\mathcal{D}_{\Sigma}; write Σ^=Σ(μ^)\hat{\Sigma}=\Sigma(\hat{\mu}). We check the hypothesis of The Mean-Field Limit of the Relative Score of Laws of Dyson Particles Concentrating at a Measure §pairing. Let ε′>0\varepsilon'>0. As q∈Tμ^q\in T_{\hat{\mu}}, the closure of the gradients of test functions (The Tangent Space of the Wasserstein Space at a Probability Measure §tangent), there is ψ∈Cc∞(R)\psi\in C_{c}^{\infty}(\mathbb{R}) with ∥q−ψ′∥μ^<ε′/3\lVert q-\psi'\rVert_{\hat{\mu}}<\varepsilon'/3; ψ′\psi' is bounded and Lipschitz with constant Lψ=max⁡∣ψ′′∣L_{\psi}=\max|\psi''|. For x∈WMjx\in W_{M_{j}} (ordered) and N=MjN=M_{j}: since μ^(Bi)=1/N\hat{\mu}(B_{i})=1/N (Quantile Blocks of an Atomless Measure on the Line: Block Maps, Distances to Ordered Empirical Measures, and the Block Test Function §blocks), xi−mi=N∫Bi(xi−s) μ^(ds)x_{i}-m_{i}=N\int_{B_{i}}(x_{i}-s)\,\hat{\mu}(ds) and the Cauchy-Schwarz inequality gives (xi−mi)2≤N∫Bi(xi−s)2μ^(ds)(x_{i}-m_{i})^{2}\le N\int_{B_{i}}(x_{i}-s)^{2}\hat{\mu}(ds), whence 1N∑i(xi−mi)2≤W(x)2\frac{1}{N}\sum_{i}(x_{i}-m_{i})^{2}\le W(x)^{2} by Quantile Blocks of an Atomless Measure on the Line: Block Maps, Distances to Ordered Empirical Measures, and the Block Test Function §optimal; with Quantile Blocks of an Atomless Measure on the Line: Block Maps, Distances to Ordered Empirical Measures, and the Block Test Function §averages for h=ψ′h=\psi' and (a+b)2≤2a2+2b2(a+b)^{2}\le2a^{2}+2b^{2},

1N∥Gj−ψ′⊕∥Qj2≤4∥q−ψ′∥μ^2+(4Lψ2+8Kj2)∫W2 dQj<4ε′29+(4Lψ2+8Kj2)∫W2 dQj,\frac{1}{N}\bigl\lVert G_{j}-\psi'^{\oplus}\bigr\rVert_{Q_{j}}^{2}\le4\lVert q-\psi'\rVert_{\hat{\mu}}^{2}+\bigl(4L_{\psi}^{2}+8K_{j}^{2}\bigr)\int W^{2}\,dQ_{j}<\frac{4\varepsilon'^{2}}{9}+\bigl(4L_{\psi}^{2}+8K_{j}^{2}\bigr)\int W^{2}\,dQ_{j},

which is below ε′2\varepsilon'^{2} for all large jj by (3). Hence

γj:=1Mj⟨ΣMj(Qj),Gj⟩Qj→⟨Σ^,q⟩μ^,ζj:=1Mj∥Gj∥Qj2→∥q∥μ^2,\gamma_{j}:=\frac{1}{M_{j}}\bigl\langle\Sigma_{M_{j}}(Q_{j}),G_{j}\bigr\rangle_{Q_{j}}\to\langle\hat{\Sigma},q\rangle_{\hat{\mu}},\qquad\zeta_{j}:=\frac{1}{M_{j}}\lVert G_{j}\rVert_{Q_{j}}^{2}\to\lVert q\rVert_{\hat{\mu}}^{2},

and by The Mean-Field Limit of the Relative Score of Laws of Dyson Particles Concentrating at a Measure §liminf, for every ε′>0\varepsilon'>0, ∥Σ^∥μ^2≤αj+ε′\lVert\hat{\Sigma}\rVert_{\hat{\mu}}^{2}\le\alpha_{j}+\varepsilon' for all large jj.

Step 5 (the lifted inequality). Fix jj, put N=MjN=M_{j} and w=w‾Nw=\overline{w}_{N}. We apply Integrating a Semiconvex Viscosity Subsolution of the Penalty-Drift Equation against a Measure of Finite Relative Fisher Information with d=Nd=N, D=WND=W_{N}, U=PNU=P_{N}, discount λ\lambda, κ=κN\kappa=\kappa_{N}, θ′=θ1,N\theta'=\theta_{1,N}, g~=gN+\tilde{g}=g^{+}_{N}, this ww, and p0=p0,Np_{0}=p_{0,N}. Its hypotheses hold: WNW_{N} is open and convex (it is cut out by finitely many strict linear inequalities, The Weyl Chamber of Ordered Points in Euclidean Space); PNP_{N} is a penalty on WNW_{N} (The N-Particle Dyson Potential on the Weyl Chamber: Penalty, Monotone Gradient, Dissipation with Constants Uniform in N, and Gibbs Integrability §penalty), hence of class C2C^{2} (Penalty on an Open Subset of Euclidean Space §regularity); λ>0\lambda>0 (The N-Particle Dyson Game and its Mean-Field Limit: Standing Data and Equations §data) and κN>0\kappa_{N}>0 (The N-Particle Dyson Potential on the Weyl Chamber: Penalty, Monotone Gradient, Dissipation with Constants Uniform in N, and Gibbs Integrability §penalty), and a=κN/2=aNa=\kappa_{N}/2=a_{N}, so DU,aΣ=DNΣ\mathcal{D}^{\Sigma}_{U,a}=\mathcal{D}^{\Sigma}_{N} and ΣU,a=ΣN\Sigma_{U,a}=\Sigma_{N}; θ1,N≥12\theta_{1,N}\ge\frac{1}{2} as Nε0≥N0ε0≥1N\varepsilon_{0}\ge N_{0}\varepsilon_{0}\ge1; gN+g^{+}_{N} is bounded and Borel on the open set WNW_{N}, so its zero extension is Borel, and ww is bounded, semiconvex with constant τ−1\tau^{-1} and a viscosity subsolution of the operator in question (Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §regularised (i), (ii), (v)); and by (iii) there, ∥Dw(x)∥2≤τ−2rN(x)2=4Nbgλτ+2τN(PN(x)−p0,N)\lVert Dw(x)\rVert^{2}\le\tau^{-2}r_{N}(x)^{2}=\frac{4Nb_{g}}{\lambda\tau}+\frac{2}{\tau N}\bigl(P_{N}(x)-p_{0,N}\bigr) at every point of differentiability. By Integrating a Semiconvex Viscosity Subsolution of the Penalty-Drift Equation against a Measure of Finite Relative Fisher Information §subsolution at μ=Qj\mu=Q_{j},

∫(λwˉ+θ1,N2∥∇w∥2−gˉN+) dQj+⟨ΣN(Qj),∇w⟩Qj≤0.\int\Bigl(\lambda\bar{w}+\frac{\theta_{1,N}}{2}\lVert\nabla w\rVert^{2}-\bar{g}^{+}_{N}\Bigr)\,dQ_{j}+\bigl\langle\Sigma_{N}(Q_{j}),\nabla w\bigr\rangle_{Q_{j}}\le0.

The map ∇w\nabla w there is Borel (Integrating a Semiconvex Viscosity Subsolution of the Penalty-Drift Equation against a Measure of Finite Relative Fisher Information §borel) and equals DwDw wherever ww is differentiable; ww is twice differentiable, hence differentiable, off a null subset of WNW_{N} (Alexandrov's Theorem for Semiconvex Functions on an Open Convex Set §ae). So ∇w\nabla w is a gradient map of ww, and Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §sub-score gives ∇w=Gj+δΣN(Qj)\nabla w=G_{j}+\delta\Sigma_{N}(Q_{j}) in L2(Qj;RN)L^{2}(Q_{j};\mathbb{R}^{N}). Expanding the square and the pairing and dividing by NN:

λ∫wˉN dQj+(θ1,Nδ22+δ)αj+(θ1,Nδ+1)γj+θ1,N2ζj−∫gˉN+N dQj≤0.(6)\lambda\int\frac{\bar{w}}{N}\,dQ_{j}+\Bigl(\frac{\theta_{1,N}\delta^{2}}{2}+\delta\Bigr)\alpha_{j}+\bigl(\theta_{1,N}\delta+1\bigr)\gamma_{j}+\frac{\theta_{1,N}}{2}\zeta_{j}-\int\frac{\bar{g}^{+}_{N}}{N}\,dQ_{j}\le0.\tag{6}

Step 6 (the zeroth-order terms). (i) lim inf⁡j∫wˉ/Mj dQj≥uˉ(μ^)\liminf_{j}\int\bar{w}/M_{j}\,dQ_{j}\ge\bar{u}(\hat{\mu}). For m∈Nm\in\mathbb{N}, The Discrete Dyson Energy per Particle: Bounds, Compactness with a Lower Limit, and Recovery Configurations with Separated Particles §recovery with μ=μ^\mu=\hat{\mu} and 1/m1/m in place of its ε\varepsilon gives LmL_{m} such that for every N≥LmN\ge L_{m} some y∈WNy\in W_{N} has W2(μyN,μ^)<1/mW_{2}(\mu^{N}_{y},\hat{\mu})<1/m and PN(y)≤N(E(μ^)+1)P_{N}(y)\le N(\mathcal{E}(\hat{\mu})+1); put Lm′=max⁡(L1,…,Lm)L'_{m}=\max(L_{1},\dots,L_{m}). For kk with Nk≥L1′N_{k}\ge L'_{1} let m(k)m(k) be the largest m≤km\le k with Nk≥Lm′N_{k}\ge L'_{m} and let xk∈WNkx^{k}\in W_{N_{k}} be such a point for 1/m(k)1/m(k); for the finitely many other kk (Nk≥kN_{k}\ge k) let xk∈WNkx^{k}\in W_{N_{k}} be arbitrary. Given mm, m(k)≥mm(k)\ge m whenever k≥mk\ge m and Nk≥Lm′N_{k}\ge L'_{m}, so W2(μxkNk,μ^)→0W_{2}(\mu^{N_{k}}_{x^{k}},\hat{\mu})\to0, and PNk(xk)≤c′NkP_{N_{k}}(x^{k})\le c'N_{k} for every kk, with c′c' the maximum of E(μ^)+1\mathcal{E}(\hat{\mu})+1 and the finitely many exceptional ratios. By Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §realising, w‾Nk(xk)/Nk→uˉ(μ^)\overline{w}_{N_{k}}(x^{k})/N_{k}\to\bar{u}(\hat{\mu}); put yj=xkj∈WMjy^{j}=x^{k_{j}}\in W_{M_{j}}. For x∈WNx\in W_{N}, N=MjN=M_{j}, Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §regularised (iv), first inequality read with yjy^{j} in place of its xx and xx in place of its yy, divided by NN, gives

w(x)N≥w(yj)N−12τ(3dj(x)2+2dj(x)rN(x)N),dj(x)=∥x−yj∥N≤W(x)+W2(μyjN,μ^),\frac{w(x)}{N}\ge\frac{w(y^{j})}{N}-\frac{1}{2\tau}\Bigl(3d_{j}(x)^{2}+2d_{j}(x)\frac{r_{N}(x)}{\sqrt{N}}\Bigr),\qquad d_{j}(x)=\frac{\lVert x-y^{j}\rVert}{\sqrt{N}}\le W(x)+W_{2}(\mu^{N}_{y^{j}},\hat{\mu}),

the bound on djd_{j} by Quantile Blocks of an Atomless Measure on the Line: Block Maps, Distances to Ordered Empirical Measures, and the Block Test Function §optimal. Integrating and using Cauchy-Schwarz, ∫wˉ/N dQj≥w(yj)/N−12τ(3Dj+2Dj1/2Rj1/2)\int\bar{w}/N\,dQ_{j}\ge w(y^{j})/N-\frac{1}{2\tau}\bigl(3D_{j}+2D_{j}^{1/2}R_{j}^{1/2}\bigr) with Dj=∫dj2 dQj≤2∫W2dQj+2W2(μyjN,μ^)2→0D_{j}=\int d_{j}^{2}\,dQ_{j}\le2\int W^{2}dQ_{j}+2W_{2}(\mu^{N}_{y^{j}},\hat{\mu})^{2}\to0 by (3), and Rj=∫rN2/N dQj=2τ(2λ−1bg+∫(PN−p0,N)/N2 dQj)≤2τ(2λ−1bg+E1+∣e∗∣)R_{j}=\int r_{N}^{2}/N\,dQ_{j}=2\tau\bigl(2\lambda^{-1}b_{g}+\int(P_{N}-p_{0,N})/N^{2}\,dQ_{j}\bigr)\le2\tau\bigl(2\lambda^{-1}b_{g}+E_{1}+|e_{*}|\bigr) by (5). This proves (i).

(ii) lim sup⁡j∫gˉMj+/Mj dQj≤g(μ^)+hτ\limsup_{j}\int\bar{g}^{+}_{M_{j}}/M_{j}\,dQ_{j}\le g(\hat{\mu})+h_{\tau}. On WNW_{N}, gN+(x)/N=g(μxN)+C0/N+ωg(rN(x)/N)g^{+}_{N}(x)/N=g(\mu^{N}_{x})+C_{0}/N+\omega_{g}(r_{N}(x)/\sqrt{N}); x↦g(μxN)x\mapsto g(\mu^{N}_{x}) is continuous on WNW_{N} (The N-Particle Dyson Game and its Mean-Field Limit: Standing Data and Equations §particle-equation) and gN+g^{+}_{N} is Borel, so each term is Borel and bounded. Let θ′′>0\theta''>0 and s>0s>0 with ∣g(μ)−g(ν)∣<θ′′|g(\mu)-g(\nu)|<\theta'' when W2(μ,ν)<sW_{2}(\mu,\nu)<s; then ∣g(μxN)−g(μ^)∣≤θ′′+2bg1{W≥s}(x)|g(\mu^{N}_{x})-g(\hat{\mu})|\le\theta''+2b_{g}\mathbf{1}_{\{W\ge s\}}(x), so by Markov's inequality ∫g(μxN) Qj(dx)≤g(μ^)+θ′′+2bgs−2∫W2dQj\int g(\mu^{N}_{x})\,Q_{j}(dx)\le g(\hat{\mu})+\theta''+2b_{g}s^{-2}\int W^{2}dQ_{j}. On Sj={x∈WN:(PN(x)−p0,N)/N2≤2λ−1bg}S_{j}=\{x\in W_{N}:(P_{N}(x)-p_{0,N})/N^{2}\le2\lambda^{-1}b_{g}\} one has rN2/N≤8τλ−1bg=2Rτ2r_{N}^{2}/N\le8\tau\lambda^{-1}b_{g}=2R_{\tau}^{2}, so ωg(rN/N)≤hτ\omega_{g}(r_{N}/\sqrt{N})\le h_{\tau}; off SjS_{j}, ωg≤2bg\omega_{g}\le2b_{g}, and as PN−p0,N≥0P_{N}-p_{0,N}\ge0, Markov's inequality and (5) give 2bgQj(WN∖Sj)≤λ(E1+∣e∗∣)/N2b_{g}Q_{j}(W_{N}\setminus S_{j})\le\lambda(E_{1}+|e_{*}|)/N. Altogether

∫gˉN+N dQj≤g(μ^)+hτ+θ′′+2bgs2∫W2dQj+C0+λ(E1+∣e∗∣)Mj,\int\frac{\bar{g}^{+}_{N}}{N}\,dQ_{j}\le g(\hat{\mu})+h_{\tau}+\theta''+\frac{2b_{g}}{s^{2}}\int W^{2}dQ_{j}+\frac{C_{0}+\lambda(E_{1}+|e_{*}|)}{M_{j}},

and (ii) follows from (3), θ′′\theta'' being arbitrary.

Step 7 (passage to the limit). θ1,Mj=1−12Mjε0→1\theta_{1,M_{j}}=1-\frac{1}{2M_{j}\varepsilon_{0}}\to1. Put c=δ22+δ>0c=\frac{\delta^{2}}{2}+\delta>0 and cj=θ1,Mjδ22+δc_{j}=\frac{\theta_{1,M_{j}}\delta^{2}}{2}+\delta. As 0≤αj≤A∗0\le\alpha_{j}\le A_{*}, (cj−c)αj→0(c_{j}-c)\alpha_{j}\to0, and by Step 4 cαj≥c(∥Σ^∥μ^2−ε′)c\alpha_{j}\ge c(\lVert\hat{\Sigma}\rVert^{2}_{\hat{\mu}}-\varepsilon') for large jj, for each ε′>0\varepsilon'>0; so lim inf⁡cjαj≥c∥Σ^∥μ^2\liminf c_{j}\alpha_{j}\ge c\lVert\hat{\Sigma}\rVert_{\hat{\mu}}^{2}. By Step 4 the third and fourth terms of (6) tend to (δ+1)⟨Σ^,q⟩μ^(\delta+1)\langle\hat{\Sigma},q\rangle_{\hat{\mu}} and 12∥q∥μ^2\frac{1}{2}\lVert q\rVert_{\hat{\mu}}^{2}. Taking the lower limit of (6) with Step 6:

λuˉ(μ^)+(δ22+δ)∥Σ^∥μ^2+(δ+1)⟨Σ^,q⟩μ^+12∥q∥μ^2−g(μ^)−hτ≤0.(7)\lambda\bar{u}(\hat{\mu})+\Bigl(\frac{\delta^{2}}{2}+\delta\Bigr)\lVert\hat{\Sigma}\rVert_{\hat{\mu}}^{2}+(\delta+1)\langle\hat{\Sigma},q\rangle_{\hat{\mu}}+\frac{1}{2}\lVert q\rVert_{\hat{\mu}}^{2}-g(\hat{\mu})-h_{\tau}\le0.\tag{7}

Step 8 (the witnesses). Take ν=μ^∈DΣ\nu=\hat{\mu}\in\mathcal{D}_{\Sigma}, π=(id,id)#μ^∈Π(μ^,μ^)\pi=(\mathrm{id},\mathrm{id})_{\#}\hat{\mu}\in\Pi(\hat{\mu},\hat{\mu}), s=uˉδ−(μ^)=uˉ(μ^)−δE(μ^)s=\bar{u}^{-}_{\delta}(\hat{\mu})=\bar{u}(\hat{\mu})-\delta\mathcal{E}(\hat{\mu}) (Step 1), the field q=∇φ(μ^)q=\nabla\varphi(\hat{\mu}) and Y=Hφ(μ^)Y=H_{\varphi}(\hat{\mu}). Then I(π)=∥id−id∥μ^2=0I(\pi)=\lVert\mathrm{id}-\mathrm{id}\rVert_{\hat{\mu}}^{2}=0 by The Displacement Pairing of a Square-Integrable Vector Field Along a Coupling §displacement; the discrepancy of qq and ∇φ(μ^)\nabla\varphi(\hat{\mu}) along π\pi equals ∫∣q(t)−q(t)∣2 μ^(dt)=0\int|q(t)-q(t)|^{2}\,\hat{\mu}(dt)=0 by the integration formula for push-forwards; and the remaining three closeness quantities of Viscosity Subsolution, Supersolution and Solution of a Second-Order Equation on the Wasserstein Space §subsolution vanish. By The Bundle of Vector Fields over a Set of Measures, Second-Order Equation Operators on the Wasserstein Space, and Their Delta-Shifts §shifted, the formula of the statement for FhτF^{h_{\tau}} (an instance of The Dyson Hamilton-Jacobi Equation with Common Noise and a Confining Potential on the Wasserstein Space of the Real Line §operator with κ=0\kappa=0, so that the matrix argument plays no role) and Σ^=V′−β4Ξμ^\hat{\Sigma}=V'-\frac{\beta}{4}\Xi_{\hat{\mu}} (The Confined Logarithmic-Energy Pair on the Wasserstein Space of the Real Line §pair), the δ\delta-shift (Fhτ)δ−(F^{h_{\tau}})^{-}_{\delta} satisfies

(Fhτ)δ−(μ^,s,q,Y)=λuˉ(μ^)+12∥q+δΣ^∥μ^2+⟨Σ^,q+δΣ^⟩μ^−g(μ^)−hτ,(F^{h_{\tau}})^{-}_{\delta}(\hat{\mu},s,q,Y)=\lambda\bar{u}(\hat{\mu})+\frac{1}{2}\lVert q+\delta\hat{\Sigma}\rVert_{\hat{\mu}}^{2}+\langle\hat{\Sigma},q+\delta\hat{\Sigma}\rangle_{\hat{\mu}}-g(\hat{\mu})-h_{\tau},

which, expanded, is the left side of (7); hence it is at most 0<ε0<\varepsilon. So uˉτ\bar{u}_{\tau} is a viscosity subsolution of FhτF^{h_{\tau}} relative to the pair.

Clause 3. Fix τ\tau, δ∈(0,1)\delta\in(0,1), φ\varphi, a point μ^\hat{\mu} at which u‾δ+−φ\underline{u}^{+}_{\delta}-\varphi has a local minimum relative to D\mathcal{D} with radius ρ\rho (Local Minimum of a Function Relative to a Subset of a Metric Space), and ε>0\varepsilon>0, as in Viscosity Subsolution, Supersolution and Solution of a Second-Order Equation on the Wasserstein Space §supersolution; write u‾=u‾τ\underline{u}=\underline{u}_{\tau}, w=w‾N,τw=\underline{w}_{N,\tau}. The proof of clause 2 applies with the following changes, and no others.

(a) Steps 1-2. u‾\underline{u} is continuous by the second inequality of Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §modulus, so the second half of Basic Properties of the Delta-Envelopes on the Wasserstein Space §exact gives u‾δ+=u‾+δE\underline{u}^{+}_{\delta}=\underline{u}+\delta\mathcal{E} on D\mathcal{D}; (1) is reversed with +δE+\delta\mathcal{E}, differentiability gives φ(ν)−φ(μ^)≥⟨q,T−id⟩μ^−ηW2(ν,μ^)\varphi(\nu)-\varphi(\hat{\mu})\ge\langle q,T-\mathrm{id}\rangle_{\hat{\mu}}-\eta W_{2}(\nu,\hat{\mu}), and (2) becomes the hypothesis of Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §super.

(b) Steps 3-4. The realising levels are those of the second half of Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §realising for u‾\underline{u} at μ^\hat{\mu}, the Gibbs laws those of Gibbs Maximisers for the Regularised N-Particle Dyson Solutions Tested at a Local Extremum: Energy Bound, Concentration and the Score Identity §super, whose (a), (b), (c) give (3), (4), (5) unchanged and ∇w=Gj−δΣN(Qj)\nabla w=G_{j}-\delta\Sigma_{N}(Q_{j}) with Gj=Mj∇χMj−G_{j}=M_{j}\nabla\chi^{-}_{M_{j}}, of components qˉi−2Kj(xi−mi)\bar{q}_{i}-2K_{j}(x_{i}-m_{i}) (Quantile Blocks of an Atomless Measure on the Line: Block Maps, Distances to Ordered Empirical Measures, and the Block Test Function §test-function with −Kj-K_{j}); the estimate of Step 4 is unchanged.

(c) Step 5. Integrating a Semiconvex Viscosity Subsolution of the Penalty-Drift Equation against a Measure of Finite Relative Fisher Information §supersolution is used, with −w-w semiconvex, θ′=θ2,N\theta'=\theta_{2,N} and g~=gN−\tilde{g}=g^{-}_{N} (Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §regularised (i), (ii), (iii), (v)); ∇w\nabla w is a gradient map by Alexandrov's Theorem for Semiconvex Functions on an Open Convex Set §ae applied to −w-w. Inequality (6) becomes

λ∫wˉN dQj+(θ2,Nδ22−δ)αj+(1−θ2,Nδ)γj+θ2,N2ζj−∫gˉN−N dQj≥0.\lambda\int\frac{\bar{w}}{N}\,dQ_{j}+\Bigl(\frac{\theta_{2,N}\delta^{2}}{2}-\delta\Bigr)\alpha_{j}+\bigl(1-\theta_{2,N}\delta\bigr)\gamma_{j}+\frac{\theta_{2,N}}{2}\zeta_{j}-\int\frac{\bar{g}^{-}_{N}}{N}\,dQ_{j}\ge0.

(d) Step 6. (i) becomes lim sup⁡j∫wˉ/Mj dQj≤u‾(μ^)\limsup_{j}\int\bar{w}/M_{j}\,dQ_{j}\le\underline{u}(\hat{\mu}): the recovery points are built identically, and the second inequality of Half-Relaxed Limits of the Sup- and Inf-Convolved N-Particle Dyson Solutions: Bounds, Continuity and Limits along Configurations of Bounded Energy §regularised (iv), with the same substitution, gives w(x)/N≤w(yj)/N+12τ(3dj2+2djrN/N)w(x)/N\le w(y^{j})/N+\frac{1}{2\tau}(3d_{j}^{2}+2d_{j}r_{N}/\sqrt{N}). (ii) becomes lim inf⁡j∫gˉMj−/Mj dQj≥g(μ^)−hτ\liminf_{j}\int\bar{g}^{-}_{M_{j}}/M_{j}\,dQ_{j}\ge g(\hat{\mu})-h_{\tau}, since gN−/N=g(μxN)−C0/N−ωg(rN/N)g^{-}_{N}/N=g(\mu^{N}_{x})-C_{0}/N-\omega_{g}(r_{N}/\sqrt{N}) and the same bounds apply.

(e) Step 7. θ2,Mj=1+1Mjε0→1\theta_{2,M_{j}}=1+\frac{1}{M_{j}\varepsilon_{0}}\to1, and the limit coefficient of αj\alpha_{j} is c=δ22−δ=δ(δ2−1)<0c=\frac{\delta^{2}}{2}-\delta=\delta(\frac{\delta}{2}-1)<0, so lim sup⁡cjαj=clim inf⁡αj≤c∥Σ^∥μ^2\limsup c_{j}\alpha_{j}=c\liminf\alpha_{j}\le c\lVert\hat{\Sigma}\rVert_{\hat{\mu}}^{2}. Taking the upper limit, (7) becomes

0≤λu‾(μ^)+(δ22−δ)∥Σ^∥μ^2+(1−δ)⟨Σ^,q⟩μ^+12∥q∥μ^2−g(μ^)+hτ.0\le\lambda\underline{u}(\hat{\mu})+\Bigl(\frac{\delta^{2}}{2}-\delta\Bigr)\lVert\hat{\Sigma}\rVert_{\hat{\mu}}^{2}+(1-\delta)\langle\hat{\Sigma},q\rangle_{\hat{\mu}}+\frac{1}{2}\lVert q\rVert_{\hat{\mu}}^{2}-g(\hat{\mu})+h_{\tau}.

(f) Step 8. The witnesses are the same with s=u‾δ+(μ^)=u‾(μ^)+δE(μ^)s=\underline{u}^{+}_{\delta}(\hat{\mu})=\underline{u}(\hat{\mu})+\delta\mathcal{E}(\hat{\mu}), and (F−hτ)δ+(μ^,s,q,Y)=λu‾(μ^)+12∥q−δΣ^∥μ^2+⟨Σ^,q−δΣ^⟩μ^−g(μ^)+hτ(F^{-h_{\tau}})^{+}_{\delta}(\hat{\mu},s,q,Y)=\lambda\underline{u}(\hat{\mu})+\frac{1}{2}\lVert q-\delta\hat{\Sigma}\rVert_{\hat{\mu}}^{2}+\langle\hat{\Sigma},q-\delta\hat{\Sigma}\rangle_{\hat{\mu}}-g(\hat{\mu})+h_{\tau}, which, expanded, is the right side above; hence −ε<0≤(F−hτ)δ+(μ^,s,q,Y)-\varepsilon<0\le(F^{-h_{\tau}})^{+}_{\delta}(\hat{\mu},s,q,Y), and u‾τ\underline{u}_{\tau} is a viscosity supersolution of F−hτF^{-h_{\tau}} relative to the pair.

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