Documentation

MIPRE.Background.LIDT.Co.SelfImprovement.Theorems.Results.AddInUStep34AndTransfer.Variance

Unselected add-in-u Step 3/4 global-variance bounds #

Unselected self-energy estimates, variance-factor comparisons, and the combined global-variance bridges for the projection-simplified add-in-u chain: the counterpart of the vendored SelfImprovement/Theorems/Results/AddInUStep34AndTransfer/Variance.lean (under MIPRE/Background/LIDT/MIPStarRE/LDT/) in the port of planning/c6b-plan.md (milestone M10, section "Port conventions").

Contents #

Every scalar is strategy.state.ev of a joint operator; opTensor A B is strategy.state.opTensor A B, leftTensor A * rightTensor B is strategy.state.L A * strategy.state.R B, and Xᴴ is star X. The vendored Hermitian facts SubMeas.outcome_hermitian … and rw [Matrix.conjTranspose_sub, …] are IsSelfAdjoint.of_nonneg and IsSelfAdjoint.sub.

Global variance. The local and global deviations are M6's (Co GlobalVariance/Defs/Families): the variances of the family u ↦ S.L (A^u_{g(u)}) * S.R √T_g on strategy.state itself, not on the vendored weighted state (M6's departure). The variance factor is identified with the global one through Co weightedPointConditionedOperator_sq, exactly where the vendored proof rewrites with its vendored counterpart, and the local-to-global step is Co globalVarianceDeviation_sum_le_of_localVarianceDeviation_sum_le; so every statement keeps its vendored text.

Dropped hypothesis. The vendored add_in_u_cs_chain_q3_q4_self_energy_factor_le_one closes with ev_one_of_isNormalized strategy.state strategy.isNormalized (vendored line 124), and add_in_u_cs_chain_q2_q3_self_energy_factor_le_one applies sandwichTensor_residual_sum_le_one strategy.state strategy.isNormalized (vendored line 207); here strategy.state.ev_one_of_isNormalized and Co SymModel.sandwichTensor_residual_sum_le_one (Basic/TensorPlacement) take no normalization hypothesis. No statement of the vendored file carries a swap, density or normalization hypothesis, so no statement changed.

Proofs. The Q₃ → Q₄ self-energy bound is pointwise in (u, v), through avgOver_uniform_le_const, rather than first collapsing the v-average with avgOver_uniform_fst as the vendored proof does; the projection collapse is Co proj_outer_sandwich_eq (AddInUDiagonalAndDefs/Selection), and the contraction Co SubMeas.opTensor_sum_filter_le_one, which takes the model as an explicit argument. The file sets no option; the vendored file-wide respectTransparency false is not needed.

The vendored module is imported for its one classical declaration; its only import is the vendored AddInUStep34AndTransfer/Factored, which Co Factored imports already.

Not ported #

References #

In LionSR/MIPStarRE at commit 507e8122, not in this repository:

theorem MIPRE.LIDT.Co.SelfImprovement.le_sqrt_of_le_sqrt_of_le {a s ζ : ℝ} (hcs : a ≤ √s) (hsum : s ≤ ζ) :
a ≤ √ζ

Upstream keeps this helper private since its Lean-module port (LionSR/MIPStarRE at 5fc363b); the port carries its own copy, with upstream's proof.

Sqrt-monotonicity transit lemma used by the two GlobalVariance endpoint bridges below: a real bounded by Real.sqrt s is bounded by Real.sqrt ζ whenever s ≤ ζ. Both Q₂→Q₃ and Q₃→Q₄ apply this fact with the same s (the summed globalVarianceDeviationAtPolynomial).

Self-energy factor ≤ 1 for the Q₃ → Q₄ factored Cauchy--Schwarz.

The first square-root factor D₁ produced by add_in_u_cs_chain_q3_q4_factored_cs is bounded by 1. The proof collapses the outer projection A^u_{h(u)} around the sandwiched submeasurement H^u_h = A^u_{h(u)} · T_h · A^u_{h(u)} via projectivity, then bounds the per-point sum of opTensor (H^u_h) (T_h) by the submeasurement-opTensor-sum lemma, lifts to expectation via ev, and averages over (u, v).

This supplies the hD₁_le_one hypothesis required by add_in_u_cs_chain_q3_q4_le_sqrt_of_factor_bounds.

Self-energy factor ≤ 1 for the Q₂ → Q₃ factored Cauchy--Schwarz.

The second square-root factor produced by add_in_u_cs_chain_q2_q3_factored_cs is bounded by 1. For fixed (u,v), the diagonal summand is one summand of the nonnegative residual tensor sum Σ_{i,r,o} A^v_o H^u_i A^v_o ⊗ T_r. The residual sum is at most 1 by sandwichTensor_residual_sum_le_one, applied to the point measurement at v, the sandwiched polynomial submeasurement at u, and the original submeasurement T.

The variance factor in the Q₂ → Q₃ factored Cauchy--Schwarz estimate is bounded by the polynomial sum of the global-variance deviations.

For each polynomial h, the sandwiched operator H^u_h is bounded by 1. Thus the summand (A^v_{h(v)} - A^u_{h(u)}) H^u_h (A^v_{h(v)} - A^u_{h(u)}) ⊗ T_h is dominated by the squared point-operator difference tensored with T_h. The latter is exactly the integrand defining globalVarianceDeviationAtPolynomial, after expanding the weighted point-conditioned operator.

The variance factor in the Q₃ → Q₄ factored Cauchy--Schwarz estimate is bounded by the polynomial sum of the global-variance deviations.

This is the same variance expression as in the Q₂ → Q₃ estimate, appearing as the second square-root factor rather than the first.

Raw Q₂ → Q₃ global-variance Cauchy--Schwarz bound after both factors have been estimated.

Raw Q₃ → Q₄ global-variance Cauchy--Schwarz bound after both factors have been estimated.

theorem MIPRE.LIDT.Co.SelfImprovement.add_in_u_cs_chain_q2_q3_le_sqrt_of_globalVarianceDeviation_sum_le {𝔓 : Type u_1} [CStarAlgebra 𝔓] [PartialOrder 𝔓] [StarOrderedRing 𝔓] {K : Type u_2} [NormedAddCommGroup K] [InnerProductSpace ℂ K] [CompleteSpace K] (params : MIPStarRE.LDT.Parameters) [MIPStarRE.LDT.FieldModel params.q] (strategy : SymStrat params 𝔓 K) (T : SubMeas (MIPStarRE.LDT.Polynomial params) 𝔓) {ζ : ℝ} (hglobal : ∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g ≤ ζ) (hcs : |addInUCSChainQ2 params strategy T - addInUCSChainQ3 params strategy T| ≤ √(∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g)) :
|addInUCSChainQ2 params strategy T - addInUCSChainQ3 params strategy T| ≤ √ζ

The global-variance sum bound upgrades the raw Cauchy--Schwarz estimate for the first global-variance replacement step into the displayed sqrt ζ bound.

This is the variance-use fragment of eq:change-one in references/ldt-paper/self_improvement.tex, lines 299--318. The hypothesis hcs is the Cauchy--Schwarz estimate eq:change-one-cauchy-schwarz (lines 306--311) after the second square root has been bounded by 1 using (A^v_{h(v)})² ≤ I and the fact that T is a measurement (lines 312--316, 318); concretely, the right-hand side is the summed globalVarianceDeviationAtPolynomial (the displayed first-square-root content). This lemma applies only the remaining ≤ ζ_variance step from lem:global-variance-of-points (line 317) via sqrt-monotonicity.

theorem MIPRE.LIDT.Co.SelfImprovement.add_in_u_cs_chain_q3_q4_le_sqrt_of_globalVarianceDeviation_sum_le {𝔓 : Type u_1} [CStarAlgebra 𝔓] [PartialOrder 𝔓] [StarOrderedRing 𝔓] {K : Type u_2} [NormedAddCommGroup K] [InnerProductSpace ℂ K] [CompleteSpace K] (params : MIPStarRE.LDT.Parameters) [MIPStarRE.LDT.FieldModel params.q] (strategy : SymStrat params 𝔓 K) (T : SubMeas (MIPStarRE.LDT.Polynomial params) 𝔓) {ζ : ℝ} (hglobal : ∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g ≤ ζ) (hcs : |addInUCSChainQ3 params strategy T - addInUCSChainQ4 params strategy T| ≤ √(∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g)) :
|addInUCSChainQ3 params strategy T - addInUCSChainQ4 params strategy T| ≤ √ζ

The global-variance sum bound upgrades the raw Cauchy--Schwarz estimate for the second global-variance replacement step into the displayed sqrt ζ bound.

This is the variance-use fragment of eq:change-another in references/ldt-paper/self_improvement.tex, lines 319--340. The hypothesis hcs is the Cauchy--Schwarz estimate of lines 326--332 after the first square root has been bounded by 1 using (A^u_{h(u)})² ≤ I and the fact that T is a measurement (lines 333--338); concretely, the right-hand side is the summed globalVarianceDeviationAtPolynomial (the displayed second-square-root content, equal to the first-square-root term of eq:change-one-cauchy-schwarz per line 340). This lemma applies only the remaining ≤ ζ_variance step (line 340) via sqrt-monotonicity.

Closed global-variance bridge for the first projection-simplified Cauchy--Schwarz replacement step.

The factor estimates proved above supply the raw square-root bound, so the only remaining hypothesis is the summed global-variance estimate.

Closed global-variance bridge for the second projection-simplified Cauchy--Schwarz replacement step.

The factor estimates proved above supply the raw square-root bound, so the only remaining hypothesis is the summed global-variance estimate.

theorem MIPRE.LIDT.Co.SelfImprovement.add_in_u_cs_chain_global_variance_steps_of_sum_bound {𝔓 : Type u_1} [CStarAlgebra 𝔓] [PartialOrder 𝔓] [StarOrderedRing 𝔓] {K : Type u_2} [NormedAddCommGroup K] [InnerProductSpace ℂ K] [CompleteSpace K] (params : MIPStarRE.LDT.Parameters) [MIPStarRE.LDT.FieldModel params.q] (strategy : SymStrat params 𝔓 K) (T : SubMeas (MIPStarRE.LDT.Polynomial params) 𝔓) {ζ : ℝ} (hglobal : ∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g ≤ ζ) (h23cs : |addInUCSChainQ2 params strategy T - addInUCSChainQ3 params strategy T| ≤ √(∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g)) (h34cs : |addInUCSChainQ3 params strategy T - addInUCSChainQ4 params strategy T| ≤ √(∑ g : MIPStarRE.LDT.Polynomial params, GlobalVariance.globalVarianceDeviationAtPolynomial params strategy strategy.state.toVecState T g)) :
|addInUCSChainQ2 params strategy T - addInUCSChainQ3 params strategy T| ≤ √ζ ∧ |addInUCSChainQ3 params strategy T - addInUCSChainQ4 params strategy T| ≤ √ζ

Combined Step 3/4 variance bridge for the projection-simplified add-in-u Cauchy--Schwarz chain.

Given the two raw Cauchy--Schwarz estimates against the summed independent-points deviation and a GlobalVariance sum bound, this produces the two sqrt ζ absolute-difference bounds needed by add_in_u_simplified_transfer_of_cs_chain. It deliberately does not assemble the final transfer, so the remaining self-consistency steps and arithmetic absorption stay separate.

Combined Step 3/4 variance bridge using the factor estimates proved in this file.

This is the closed form of add_in_u_cs_chain_global_variance_steps_of_sum_bound: the raw Cauchy--Schwarz estimates are supplied by add_in_u_cs_chain_q2_q3_le_sqrt_globalVarianceDeviation_sum and add_in_u_cs_chain_q3_q4_le_sqrt_globalVarianceDeviation_sum.

Local-variance-sum version of the combined Step 3/4 variance bridge.

This consumes the expected output of the local-variance normalization step (expansion.tex, lines 317--321) through globalVarianceDeviation_sum_le_of_localVarianceDeviation_sum_le, then applies the combined Step 3/4 bridge above. It remains a named bridge because the blueprint cites this local-sum interface separately from the closed factor-bound lemma below.

Closed local-variance bridge for the first projection-simplified Cauchy--Schwarz replacement step.

The local-variance sum estimate is first transported to the corresponding global-variance estimate, and the factor estimates provide the raw Cauchy--Schwarz bound.

Closed local-variance bridge for the second projection-simplified Cauchy--Schwarz replacement step.

The local-variance sum estimate is first transported to the corresponding global-variance estimate, and the factor estimates provide the raw Cauchy--Schwarz bound.

Local-variance-sum version of the combined Step 3/4 variance bridge using the factor estimates proved in this file.

This is the closed local-sum form of add_in_u_cs_chain_global_variance_steps_of_sum_bound_from_factor_bounds: the only new input is the local-variance sum hypothesis, which is first transported to the global-variance sum bound.