We prove a finite-depth access-threshold separation theorem for public quantum records. In a single four-branch many-body environment, one label is encoded in a positive-rate, positive-distance quantum code while a second label is redundantly broadcast in local environmental degrees of freedom. Although unrestricted global decoding selects the encoded record, every public fragment below a distance/light-cone threshold has exactly zero distinguishability for that record, while the broadcast label remains publicly distinguishable with positive density. Conversely, above a complementary high-access threshold, erasure recovery reconstructs the encoded record. The result formalizes a separation between globally decodable environmental information and public objectivity under a declared fragment-access structure.
We prove a finite-depth access-threshold separation theorem for public quantum records. In a single four-branch many-body environment, one label is encoded in a positive-rate, positive-distance quantum code while a second label is redundantly broadcast in local environmental degrees of freedom. Although unrestricted global decoding selects the encoded record, every public fragment below a distance/light-cone threshold has exactly zero distinguishability for that record, while the broadcast label remains publicly distinguishable with positive density. Conversely, above a complementary high-access threshold, erasure recovery reconstructs the encoded record. The result formalizes a separation between globally decodable environmental information and public objectivity under a declared fragment-access structure.
Quantum Darwinism and related objectivity frameworks study how information about a quantum system is redundantly recorded in its environment. This preprint studies a downstream selection problem: when several candidate records coexist, which one is public under a specified access channel? The problem is formulated as access-limited quantum hypothesis testing. The global Chernoff distinguishability of a candidate record is compared with the public Chernoff distinguishability after a declared sequence of completely positive trace-preserving access maps. The main result is a sufficient access-algebra separation mechanism: if a broadcast record has extensive distinguishability inside the public access algebra, while a globally stronger encoded record is hidden from that algebra at subextensive rate, then global information density and public distinguishability density have opposite thermodynamic orderings. This is not a definition of objectivity in the sense of Spectrum Broadcast Structure or Strong Quantum Darwinism; it is an operational separation theorem for a declared public decision problem. The preprint gives a random-linear access-algebra construction and controlled realizations based on code distance, local circuits, operator spreading, and protected Hamiltonian access algebras.
This paper is the seventh in a sequence developing an interpretive framework that redescribes physical reality as a causally consistent history of information updates rather than as a collection of objects independently existing within spacetime. Two prior results set up its question. The third paper (Uchida, 2026c) characterized public finality—recoverability of a committed fact by many mutually independent accessors, non-disturbingly and repeatably—as a broadcast redundancy: an effectively classical pointer value proliferated across many disjoint environmental fragments, approximately in the form of spectrum broadcast structure. The fourth paper (Uchida, 2026d) read the evaporating black hole as the regime in which a committed interior record crosses, at the Page time, from hidden to recoverable encoding, reconstructible from the radiation through entanglement-wedge reconstruction; and the parent framework (Uchida, 2026a, §10) had flagged holographic quantum error correction as a place its language of protected, redundantly encoded, locally recoverable records might find content. The present paper makes that content precise as a structure theory of recoverable records, kept separate from any claim of new physics or any suggestion that the framework derives the underlying results. The central claim is conditional and structural. The framework does not claim that every recoverable piece of information is a code, that the universe is literally a quantum error-correcting code, or that AdS/CFT describes our universe. It claims that when information qualifies as an erasure-recoverable record because an encoding preserves a logical degree of freedom—or a logical operator algebra—against a specified family of physical erasures, then that recoverability is formalized as an exact or approximate quantum error-correcting structure, in which each correctable erasure leaves an authorized complementary region supporting a recovery map. That formalization is itself an established mathematical classification; the paper's interpretive contribution is to read the series' recoverable record through it, and to set it against a second, distinct architecture. Broadcast redundancy makes the same effectively classical value legible from many disjoint fragments; erasure-correcting redundancy protects noncommuting logical quantum information by keeping each correctable erased region ignorant of—approximately private with respect to—the protected logical content, while suitable remaining regions recover it. The formal engine of this distinction is the duality between correctability and privacy (the information–disturbance tradeoff), not the no-cloning theorem; no-cloning, with the access structure of quantum secret sharing, survives as the reason independently usable recovery regions for arbitrary unknown logical quantum information must overlap. Three commitments keep the reading honest. First, it separates three senses of "record"—protected logical quantum information, a committed classical record, and a publicly final record—and insists that recovery or decoding restores access to logical quantum information but does not, by itself, commit a classical value; commitment additionally requires measurement, pointer imprinting, decoherence, and stabilization (Uchida, 2026f), and public finality a still later broadcast. Second, holographic quantum error correction is offered as the sharpest worked model of the distinction, with exactly solvable tensor-network toy codes (exact within the model) kept distinct from realistic semiclassical holographic reconstruction beyond those limits (generally treated as approximate), and both from the further question of state-dependence. Third, code-recoverability does not by itself imply public finality: protected quantum information can be recoverable from authorized regions while remaining non-public. The framework relabels code structure as the architecture of recoverability and derives none of it, making no independent empirical prediction. Its disciplined thesis is that codes protect recovery; broadcasts create publicity—different architectures that a single physical history may nonetheless realize in sequence.
This paper is the twenty-ninth in a sequence developing an interpretive framework that redescribes physical reality as a causally consistent history of information updates rather than as a collection of objects independently existing within spacetime. It returns the series to its physics-of-records basement after a long ascent through semantics, epistemology, agency, and the constitutive foundations of normative standing. Its question is narrow and physical: when does a quantum record that has been redundantly encoded in the environment count as a warranted public record — a record fit to be treated as shared, independently checkable, finality-graded evidence? Two prior papers already settled what this paper deliberately does not re-derive. Paper 3 established the world-side form of public finality for quantum records: a publicly final fact must be effectively classical pointer information, redundantly encoded across many disjoint environmental fragments, satisfying a demand-side redundancy bound, drawing on no-broadcasting, spectrum broadcast structure, and quantum Darwinism. Paper 8 separated, inside quantum mechanics, the temporal address of a record from its formation. The present paper adds the type-separation those two leave open: relational temporal address is not physical publicity capacity, and physical publicity capacity is not warranted public standing. The central result is a separation, not a new piece of physics. On the framework's declared anti-luck conception of warrant, meeting Paper 3's redundancy bound is necessary but not sufficient for warranted public standing. This is made precise in two steps. Unconditionally, two histories are constructed that realize the identical audited reduced state on the system and its environmental fragments — and, where stability is at issue, the identical audited reduced process over an audit interval — hence the identical spectrum-broadcast structure, redundancy, fidelity, and accessibility, so that no functional of the audited state alone can tell them apart — yet whose target-relative provenance profiles differ: in one, the fragments branch after the recorded event into mutually independent system–environment interactions; in the other, they pass after that event through an additional common source. It follows that provenance admissibility is not a functional of the audited quantum state. Conditionally, under a declared anti-luck calibration in which the second history's additional common bottleneck, selective retention, and closed challenge path constitute a defeater, the two histories receive different warranted-public-standing profiles. So warranted public standing tracks provenance, not redundancy alone — and not by stipulation, but because a recovery whose apparent independent agreement is an artifact of a single source is, in the series' anti-luck sense, unwarranted. The quantum publicity ceiling itself — that only effectively commuting content can be exactly public — is imported as background, not claimed as novel. The paper further shows that no quantum record certifies its own warranted public standing from inside, and that an adequate relational temporal address does not by itself confer public standing. All of this holds without a Global Bookkeeper: no physically privileged subsystem inside a consistency-constrained quantum information history supplies, primitively and globally, a non-contextual valuation, a privileged simultaneity, a canonical subsystem cut, a unique classical history, a self-certifying finality, or a global reference frame. ALAC Paper 29. First panel of the eighth grouping — a foundational-physics trilogy (29 Public Quantum Records -> 30 Classicality Without a Global Classicalizer -> 31 Spacetime Localization Without a Global Frame). Part of the Consistency-Constrained Information History (Akashic Ledger Architecture Cosmology) series.
Quantum Darwinism identifies objectivity with redundant environmental records of system information. A complementary question arises when more than one finite-strength diagnostic record is available to an observer with a declared access rule: which record is selected at a given fragment size? We formulate this question as a context-indexed public-record selector and derive a microscopic asymptotic mechanism for access-scale inversion. The model contains a central qubit coupled simultaneously to a local spin-meter bath that records a σz diagnostic and to a critical transverse-field Ising bath that records a σx diagnostic through the Ising order parameter. For contiguous fragments of length ℓ, the local meter gives trace-distance evidence Fz(ℓ,t)=Cz(t)ℓ+o(ℓ), whereas the critical bath gives Fx(ℓ,t)=Cx(t)ℓ^{7/4}+o(ℓ^{7/4}) in the Ising scaling regime. With public amplitude A_i^pub(ℓ)=[R(ℓ)F_i(ℓ)]^{1/2} and block redundancy R(ℓ)=N/ℓ, the local record is selected at small access scales but the critical record is selected for ℓ>ℓc, with ℓc=[Cz(t)/Cx(t)]^{4/3} up to sector-size and scaling corrections. The crossover is not simultaneous perfect broadcasting of incompatible observables; it is a context-indexed finite-record selection rule. An exact free-fermion/Toeplitz scaling check of the critical bath gives a block-susceptibility exponent consistent with 7/4, while exact diagonalization of a small noncommuting Hamiltonian and parameter scans are included as finite-size pilots of the selector mechanism. This record is a public preprint/manuscript version and has not been peer-reviewed as a journal publication.
Abstract Decoherence suppresses interference, but an observer’s ability to reconstruct a classical pointer value depends on additional resources: distinguishable conditional environmental states, an allowed measurement, sufficient accessible fragments, and sufficiently independent records. We provide an explicit minimal quantum-to-operational bridge that places these requirements in one chain. A system qubit is correlated with conditional environmental qubit states, permitting exact expressions for residual coherence, quantum mutual information, pointer Holevo information, accessible information, and Helstrom discrimination error. Full density-matrix calculations validate the formulas across 280 endpoint and interior cases. An accessible-sector/hidden-bath construction shows that coherence can fall below 2.3 × 10⁻⁵ while the observer’s record information and error remain fixed at 0.0803 bits and 0.4009. Measurement policies shift recovery thresholds: for record overlap 0.8 and error tolerance 0.05, collective or optimized adaptive-local discrimination requires four fragments, a fixed canonical-basis measurement requires six, and repeated one-fragment Helstrom measurements followed by classical decoding require seven. More importantly, records matched at the one-fragment level can have radically different collective behavior. For a binary pointer, the common-mode classical channel has an exact accessible-information ceiling of 1 − h₂(0.1) = 0.5310 bits, while the noncommuting hidden-memory ensemble approaches the same Holevo-information ceiling; matched independent records approach one bit and zero error. Disjoint observer counts and unanimous agreement likewise depend on shared error structure. Finally, declared local measurements induce classical record channels that are subjected to held-out model selection, predictive checks, abstention, and simultaneous finite-sample threshold certification. The resulting framework supplies the validated quantum-to-operational record model used in the companion analysis of operational capacity bounds for distinguishable decoherent histories.
A quantum record can have locally accessible populations while its distinguishing phase remains correlated with a distant source. We study this access boundary in a specified finite recording apparatus with a returning, vacuum/one-excitation source. Source-position weights give finite-time cutoff bounds without removing any physical hopping or return coupling. For an initially far-tagged record and its incoherent mixture, every reader in a declared position-preserving local-control class obeys a phase-visibility envelope and a necessary access-time inequality. A separate finite local probe shows why that state-discrimination limit is not an unrestricted limit on distinguishing two dynamical laws: fresh local coherence can reveal a stipulated added dephaser without recovering the old record phase. We construct a bounded, degree-three reader accessing only source positions 1–32. With the initial tag fixed at position 65, exact finite-source arrival certificates and an analytical tail comparison yield recovery uniformly over every finite total source length at least 65. Accessible control faults are charged against the arrived signed-phase norm, while source-moving drift is charged against the full norm. At the fixed deadline 25.02/J, the matched phase-dependent difference between coherent and archive-gated dynamics exceeds 0.005, including the stated simultaneous control faults and four additional absolute response allowances of 0.008 each. Complementary results cover a vacuum-ready source and a stronger endpoint-prepared finite example. The conclusions are conditional on the supplied model, preparations, common realized controls and calibration bounds. They are not a switchable-fundamental-law experiment, a nuisance-independent classifier, an optimal-speed theorem or an end-to-end formal verification. The supporting Lean companion contains 59 declarations in eight modules with accepted returned Mac compilation, type and axiom evidence; physical analytical interfaces remain explicit hypotheses or outside that subset. The deposit files include the main manuscript, technical supplement and full research/reproduction package.