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Split-class screened supply

Part of the fixed-cut archive, Chapter The fixed cut: remaining problems; the reading order is on the full proofs page.

Overview. This dossier proves Proposition 29.3 in total-budget form, on the regular split class (Theorem D25.1). For a product of isotropic one-dimensional log-concave laws and a cut depending on kk coordinates, the screened weighted excess over [0,T∧τη][0,T\wedge\tau_\eta] is at most (2k+64η2(1+k))/κ(2k+64\eta^2(1+k))/\kappa ((D25.4)), uniformly in TT, nn and the spectators. It is not a C(k) TC(k)\,T estimate. On the screen the weighted excess is dominated by the Stein source QtQ_t, and QtQ_t is then paid from the coordinate source and dissipation budgets. The passage to general split laws is left open (Remark D25.3).

  1. On the screened set, etWcut≤Qt/κe_tW_{\rm cut}\le Q_t/\kappa pathwise ((D25.5)). This uses only et≥0e_t\ge0 and gives (D25.6).

  2. In the tight window, Lemma 32.1 converts QtQ_t into 2St+64η2Dt2S_t+64\eta^2D_t ((D25.8)).

  3. Lemma 31.1 and Corollary 24.1 give the source budget E∫0∞St  dt≤k\E\int_0^\infty S_t\,\dd t\le k ((D25.9)).

  4. Theorem 24.1 with optional stopping and step 3 gives the dissipation budget 1+k1+k ((D25.12)). Chaining steps 1–4 proves the theorem.

  5. Separately, Lemma D25.1 extends Corollary 30.1 to a Carleson input with an additive constant. By Grönwall and Doob, the mass survives in the window up to a time T∗T_* with probability at least 1/21/2, and Lemma 30.1 turns this into a perimeter bound. No screened trace companion and no KLS conclusion is claimed (Remark D25.4).

Scope. This dossier proves the screened weighted-excess supply estimate for coordinate cuts on products of isotropic one-dimensional log-concave measures, in total-budget form: the bound is a constant depending only on the number kk of active coordinates, the window half-width η\eta, and the screening ratio κ\kappa; it is uniform in the horizon TT, in the ambient dimension nn, and in every spectator coordinate. It is not an estimate of the form C(k) TC(k)\,T, and no claim of that fixed-time or linear-in-TT shape is made here. The dossier asserts nothing about the trace-upgrade cluster (Conjecture 29.1, the high-rank part of Conjecture 29.3, Conjecture 31.1); in particular it neither proves nor compares any occupation estimate of that cluster, in compliance with repository constraint 6. A separate auxiliary lemma (Lemma D25.1 below) records the constant-supply extension of Corollary 30.1; it is logically independent of the main proposition and is clearly separated from it.

Regularity and measurability conventions. We adopt the following conventions:

(M1) We work on the usual P\Prob-augmented right-continuous filtration of the driving nn-dimensional Brownian motion of Eldan’s stochastic localization.

(M2) Regular split class. The main theorem is stated and proved for initial data in the compact-smooth product-preserving regularity class of the certified Riccati-core and excess-audit dossiers (kls-localization-riccati-core.md and kls-excess-audit.md, both under solutions/): each factor μ(i)\mu^{(i)} is a compactly supported one-dimensional log-concave law with smooth density, normalized to mean zero and variance one, and the cut E=EJ×RJcE=E_J\times\R^{J^c} is measurable with respect to the coordinates in JJ with EJ⊂RJE_J\subset\R^{J} having C2C^2 relative boundary with a tubular neighborhood over the support, so that P0(E)<∞P_0(E)<\infty and the one-sided tube formula identifies the lower outer Minkowski perimeter with weighted surface area. On every bounded time interval all stochastic integrals below are true martingales after the usual bounded stopping, with regularization-independent constants. Passage to general split laws and cuts is discussed, and its unresolved part explicitly flagged, in Remark D25.3 below.

(M3) Pt=Pt(E)=μt+(E)P_t=P_t(E)=\mu_t^+(E) is the lower outer Minkowski perimeter, realized pathwise as the increasing limit of infima over the fixed countable rational boundary-layer family of bounded continuous mass martingales (Lemma 32.3, construction of solutions/kls-excess-audit.md); as a pathwise monotone limit of countable infima of continuous adapted processes it is progressively measurable. In the regular class the localized density field is jointly measurable and positive, and the moving profile value Iμt(pt)I_{\mu_t}(p_t) is jointly measurable in (t,ω)(t,\omega) via a fixed countable regular competitor family; hence the excess

et  =  et(E)  =  Pt(E)−Iμt(pt)e_t \;=\; e_t(E)\;=\;P_t(E)-I_{\mu_t}(p_t)

is progressively measurable. This is a measurability convention only: no supermartingale or martingale property of the moving profile infimum is asserted (the caveat of Lemma 32.5 is preserved), and no lower bound on Iμt(pt)I_{\mu_t}(p_t) is used anywhere in this dossier.

(M4) On {0<pt<1}\{0<p_t<1\} the processes AtA_t, KtK_t, QtQ_t below are continuous and adapted in the regular class, and the map (A,K)↦λcut(A,K)(A,K)\mapsto\lambda_{\rm cut}(A,K) is Borel on supported pairs {(A,K):A⪰0, K=PRan⁡A K PRan⁡A}\{(A,K):A\succeq0,\ K=P_{\operatorname{Ran}A}\,K\,P_{\operatorname{Ran}A}\} (fixed-rank strata together with the Borel Moore–Penrose formula (D13.3) of solutions/lem-lyapunov-stein-duality.md, with the separate convention λcut(A,0)=0\lambda_{\rm cut}(A,0)=0). Hence the weight Wcut(At,Kt)W_{\rm cut}(A_t,K_t) and the screened indicator 1Aκ,t=1{Qt−κetWcut(At,Kt)≥0}\one_{\mathcal A_{\kappa,t}}=\one_{\{Q_t-\kappa e_tW_{\rm cut}(A_t,K_t)\ge0\}} are progressively measurable. Both appear only inside nonnegative Lebesgue-time integrals, handled by Tonelli; no Itô differential is ever taken of the weight, of the indicator, or of any function of λcut\lambda_{\rm cut}.

Notation. Fix the manuscript localization notation: pt=μt(E)p_t=\mu_t(E), qt=1−ptq_t=1-p_t, st=ptqts_t=p_tq_t, δt=mtE−mtF\delta_t=m_t^E-m_t^F, Gt=ΣtE−ΣtFG_t=\Sigma_t^E-\Sigma_t^F, Kt=Gt+(qt−pt)δtδtTK_t=G_t+(q_t-p_t)\delta_t\delta_t^T, Bt=stδtδtTB_t=s_t\delta_t\delta_t^T, Rt=At−BtR_t=A_t-B_t, rt=Tr⁡Bt=st∣δt∣2r_t=\Tr B_t=s_t\abs{\delta_t}^2, St=st∥Gt∥HS2S_t=s_t\norm{G_t}_\HS^2, and Dt=2stδtTAtδt−rt2≥rt2≥0D_t=2s_t\delta_t^TA_t\delta_t-r_t^2\ge r_t^2\ge0 (Theorem 24.1). Set

Qt  =  st∥Kt∥HS2  =  Sμt(E)st,Q_t\;=\;s_t\norm{K_t}_\HS^2\;=\;\frac{\calS_{\mu_t}(E)}{s_t},

the second equality being the certified Stein-norm identity Sν(E)=s2∥K∥HS2\calS_\nu(E)=s^2\norm K_\HS^2 of Proposition 32.1. With the convention λcut(A,0)=0\lambda_{\rm cut}(A,0)=0 of Lemma 30.3, put

Wcut(A,K)  =  (1+λcut(A,K))5/2,Aκ,t  =  {Qt ≥ κ et Wcut(At,Kt)}.W_{\rm cut}(A,K)\;=\;\bigl(1+\lambda_{\rm cut}(A,K)\bigr)^{5/2}, \qquad \mathcal A_{\kappa,t}\;=\;\bigl\{Q_t\ \ge\ \kappa\,e_t\,W_{\rm cut}(A_t,K_t)\bigr\}.

Finally, for η∈(0,1/4]\eta\in(0,1/4] let τη=inf⁡{t≥0:∣pt−1/2∣>η}\tau_\eta=\inf\{t\ge0:\abs{p_t-1/2}>\eta\} be the continuous-exit time of solutions/kls-localization-riccati-core.md; it is a stopping time for the augmented right-continuous filtration because pp has continuous paths.

Refined statement. The theorem below is the verbatim statement of the candidate ledger node prop:split-screened-supply, restricted per convention (M2) to the regular split class; Remark D25.3 records the approximant convention for general split laws together with the explicit unresolved limit-interchange gap.

Auxiliary lemma: constant-supply extension of tight-window consumption

The following lemma is not part of Theorem D25.1 and is not needed by its proof. It extends the certified Corollary 30.1 by allowing a constant additive term in the absorptive Carleson input — exactly the shape a total-budget supply such as (D25.4) would feed, as recorded in Section 1 of the probe. It is stated in the general (not split-specific) localization setting of the certified Riccati dossier, in the regular class of (M2) with its regularization-independent constants.

Obstructions respected.