Documentation

CsdLean4.CV.CarrierPersistence

CV-20: carrier persistence priced by locality (H7, level 1) #

Category: 3-Local (CV track; CSD-free construction).

The first statements in which a record carrier's stability is priced by field locality rather than posited (specs/BACKLOG.md H7). Framing constraint, binding per the row: these are theorems about carriers — the present-tense evolution of readout observables — never about "the past changing"; the record event is trajectory-indexed and invariant by construction (the level-2 lemmas in Empirical/CSD/QuantumChaos/CarrierPersistence.lean), and information is conserved outright (perturbed_overlap_invariant below — every global overlap is exact at every period, so what a perturbation does to a carrier is relocation, never loss).

Scope #

Finite cutoff throughout (K modes, N levels); the base drive is the kicked diagonal-phase family (graphInteractingU), the perturbation W an arbitrary unitary with stated support. The ontic-level lift (feeding the derived rate into recordFlip/recordIntact_compl_measure_le) is recorded in the H7 row as the remaining level; the operational-fixedness clause (d) is the finite-arena csd_repeatability_same, cited at level 2.

(c1) Exactness in the cone-complement #

theorem CSD.CV.heisenberg_perturbed_pow_eq {K N : } {Q R : Finset (Fin K)} (τ lam : ) (E : Finset (Fin K × Fin K)) (g : Fin K × Fin KFin NFin N) {W : (Matrix.unitaryGroup (FieldConfig K N) )} (hW : SupportedOn R W) {B : Matrix (FieldConfig K N) (FieldConfig K N) } (hB : SupportedOn Q B) (n : ) (hdisj : Disjoint (graphBall E Q n) R) :
heisenberg ((graphInteractingU K N τ lam E g * W) ^ n) B = heisenberg (graphInteractingU K N τ lam E g ^ n) B

Exactness in the cone-complement. Perturbing each period of the interacting drive by an arbitrary unitary W supported on R leaves the Heisenberg evolution of a Q-supported readout exactly unchanged for n periods, provided the coupling graph's n-ball of Q is still disjoint from R: the readout's cone has not reached the perturbation, so every W-conjugation acts trivially on the evolved readout (heisenberg_eq_of_disjoint).

(c1′) Einselection of the configuration basis #

Conjugation by a diagonal unitary fixes every diagonal observable.

theorem CSD.CV.heisenberg_diagonal_pow_eq {K N : } (τ lam : ) (E : Finset (Fin K × Fin K)) (g : Fin K × Fin KFin NFin N) (n : ) (b : FieldConfig K N) :

Einselection of the configuration basis: a diagonal readout is exactly invariant under the whole diagonal-phase drive family — every coupling graph, every strength, every period count. Carriers written in the pointer (configuration) basis are eternally intact under every diagonal drive; only genuinely non-diagonal perturbations can move them.

(c2) The bounded half #

theorem CSD.CV.norm_unitary_pow_sub_pow_le {ι : Type u_1} [Fintype ι] [DecidableEq ι] [Nonempty ι] (X Y : (Matrix.unitaryGroup ι )) (n : ) :
↑(X ^ n) - ↑(Y ^ n) n * X - Y

Iterated unitary steps separate at most linearly: ‖Xⁿ − Yⁿ‖ ≤ n·‖X − Y‖ (one fresh X − Y per period, the other factors isometries).

theorem CSD.CV.norm_mul_sub_self_le {ι : Type u_1} [Fintype ι] [DecidableEq ι] [Nonempty ι] (U W : (Matrix.unitaryGroup ι )) :
↑(U * W) - U W - 1

The per-period perturbation distance: ‖UW − U‖ ≤ ‖W − 1‖.

Conjugation contracts: ‖heisenberg U B‖ ≤ ‖B‖.

theorem CSD.CV.heisenberg_perturbed_pow_dist_le {K N : } [NeZero N] (U W : (Matrix.unitaryGroup (FieldConfig K N) )) (B : Matrix (FieldConfig K N) (FieldConfig K N) ) (n : ) :
heisenberg ((U * W) ^ n) B - heisenberg (U ^ n) B 2 * n * W - 1 * B

The bounded half: with no geometric hypothesis, n perturbed periods move any readout by at most 2n·‖W − 1‖·‖B‖ — the Duhamel rate of heisenberg_dist_le, telescoped.

★★ The window form — the H7 level-1 headline #

theorem CSD.CV.carrier_persistence_window {K N : } [NeZero N] {Q R : Finset (Fin K)} (τ lam : ) (E : Finset (Fin K × Fin K)) (g : Fin K × Fin KFin NFin N) {W : (Matrix.unitaryGroup (FieldConfig K N) )} (hW : SupportedOn R W) {B : Matrix (FieldConfig K N) (FieldConfig K N) } (hB : SupportedOn Q B) {m n : } (hmn : m n) (hdisj : Disjoint (graphBall E Q m) R) :
heisenberg ((graphInteractingU K N τ lam E g * W) ^ n) B - heisenberg (graphInteractingU K N τ lam E g ^ n) B 2 * ↑(n - m) * W - 1 * B

★★ Carrier persistence, the window form. A readout supported on Q, evolved under the interacting drive perturbed each period by an arbitrary unitary W supported on R: if R is outside the readout's m-ball, the deviation after n ≥ m periods is at most 2·(n − m)·‖W − 1‖·‖B‖exactly zero until the cone arrives, the Duhamel rate only after. Locality supplies the isolation window; the rate is derived, not posited.

(b) Information conservation, instantiated #

Every global overlap is exactly conserved under the perturbed drive, at every period: what a perturbation does to a carrier is relocation, never loss. Instantiates the Floquet-interface conservation law at the perturbed CV drive.