We address the screen problem—why a spatially delocalized quantum input interacting with a macroscopic detector yields a single localized, persistent dot on each trial. The approach is record-first: a dot is treated as an operationally certified record, stable, redundantly witnessed, and readable, and the measurement problem is reformulated as the problem of when such records become single-valued facts. To avoid semantic collapse, subsystem structure is grounded in locality via a net of local observable algebras rather than an assumed Hilbert-space tensor factorization. The paper then introduces an exact notion of certification in algebraic terms: distinct outcomes are exactly certified when they induce disjoint GNS representations of the quasi-local algebra, as can occur through outcome-dependent infrared or asymptotic dressing. In that regime, a Record Superselection Axiom (RSA) follows as a sector constraint on physically admissible quasi-local observables, excluding cross-sector interference measurements after certification. This yields a no-smear lemma for single events, supports the canonical Born weights on consistent record-history families, and implies a Wigner–Friend recoherence no-go past exact certification. Finally, the paper proposes an in-principle discriminator: in a complete witness-capture unmeasurement protocol, unitary-only accounts predict recoverable interference as capture and control approach unity, whereas exact sector disjointness predicts a principled obstruction once outcomes enter disjoint sectors. The result is a bounded, testable framework linking records, locality, and admissibility in a concrete resolution of the screen problem.
We address the screen problem—why a spatially delocalized quantum input interacting with a macroscopic detector yields a single localized, persistent dot on each trial. The approach is record-first: a dot is treated as an operationally certified record, stable, redundantly witnessed, and readable, and the measurement problem is reformulated as the problem of when such records become single-valued facts. To avoid semantic collapse, subsystem structure is grounded in locality via a net of local observable algebras rather than an assumed Hilbert-space tensor factorization. The paper then introduces an exact notion of certification in algebraic terms: distinct outcomes are exactly certified when they induce disjoint GNS representations of the quasi-local algebra, as can occur through outcome-dependent infrared or asymptotic dressing. In that regime, a Record Superselection Axiom (RSA) follows as a sector constraint on physically admissible quasi-local observables, excluding cross-sector interference measurements after certification. This yields a no-smear lemma for single events, supports the canonical Born weights on consistent record-history families, and implies a Wigner–Friend recoherence no-go past exact certification. Finally, the paper proposes an in-principle discriminator: in a complete witness-capture unmeasurement protocol, unitary-only accounts predict recoverable interference as capture and control approach unity, whereas exact sector disjointness predicts a principled obstruction once outcomes enter disjoint sectors. The result is a bounded, testable framework linking records, locality, and admissibility in a concrete resolution of the screen problem.
This paper argues that the quantum measurement problem is not a single explanatory gap but a collection of distinct tasks. We separate detector representability, probability structure, single-event actuality, and outcome-conditioned refinement, and distinguish all four from causal registration, the physical criterion by which an already-instantiated event becomes a completed measurement record. These are explanatory roles within one measurement phenomenon rather than successive temporal stages. The analysis begins from the contrast between a global quantum description containing several detector-correlated components and the single entry that appears in a realized measurement history. Rather than compressing this contrast into an unexplained transition often labeled “collapse,” we ask which specific explanatory constraints must be satisfied before the relation between the two descriptions can be diagnosed precisely. A finite-resolution alternating position–momentum history is used throughout to separate questions of record formation, probability, actuality, causal registration, and outcome-conditioned refinement. A continuum analysis shows that making the registered history arbitrarily dense does not by itself recover a classical trajectory. Several parts of the architecture are exact once their inputs are specified. A detector representation induces an exact quotient; a specified acquisition channel and record family induce system-side effects; and a specified quantum instrument determines a family of subnormalized conditional branches before any one outcome is instantiated. Given a realized outcome label, the same instrument determines the corresponding normalized outcome-conditioned state. A finite-dimensional acquisition model explicitly realizes the representability chain, while a record-algebra indistinguishability result shows that removing coherence between detector-record sectors can leave all expectation values in the lifted record algebra unchanged even when that coherence remains detectable in a richer context. These results sharpen, but do not dissolve, the measurement problem. Record structure does not derive Born weights; a probability law does not itself constitute the event realized in one run; a mathematically available conditional branch family does not select one branch condition as actual; and causal onset, stabilization, registration, and conditional refinement all presuppose or follow that event rather than produce it. The resulting constraint audit tests—without assuming—the hypothesis that global quantum multiplicity and detector-record definiteness may belong to different representational levels. The main conclusion is not a new collapse dynamics but a localization of the remaining explanatory burden. Once representability, probability, causal registration, and conditional refinement are assigned their proper roles, the unresolved actuality transition can no longer be hidden inside the single label “collapse.” In the typed measurement architecture considered here, no pre-event operation has the mathematical role of producing an individual event token without additional event-producing structure. This is version 1.0 of the manuscript.
When initially disjoint observers later consult physical records, under what specified conditions should their readouts agree? This paper gives a sufficient, access-relative certification within standard quantum mechanics. This certification requires stable, repeatably readable labels, low accessible sensitivity to coherence between the corresponding outcome sectors, and, for distributed consultation, carriers encoding a common label. Sequential nondemolition readouts of a single carrier with orthonormal record labels produce memory registers whose product record-basis outcomes match with Born probability one, independently of coherence in the carrier. For disjoint carriers, if their accessible joint state is close in trace distance to the corresponding marginal of an ideal spectrum broadcast structure, disagreement is bounded by that distance and by the two local discrimination errors. In a two-outcome model, the relevant coherence belongs to the branch-bearing system-record state rather than the record-only marginal; defining dephasing and off-diagonal observables on that same space yields an interference bound. These results concern record statistics, not interpretation-neutral identity of first-person experiences or observer-independent reality. Applied to Extended Wigner’s Friend scenarios, they support ideal ask-the-friend agreement. That fixed-setting equality supplies neither the setting-indexed joint model required by Absoluteness of Observed Events in Local Friendliness nor Brukner’s common Boolean representation, and it does not entail Frauchiger and Renner’s distinct quantum certainty, inter-agent-consistency, and single-valuedness assumptions. The no-go results remain valid conditional consequences of those premises.
Papers I and II derived gravitational geometry and second-order dynamics from finite accessibility without invoking measurement, observation protocols, or collapse as primitive notions. This paper extends the operational program to the measurement sector, deriving the structure of record formation and probabilistic weights from the same finite accessibility and compositional constraints. Finite accessibility restricts admissible operations on a subsystem to a proper operator subalgebra. Because bounded certification excludes operators requiring nonlocal coordination or arbitrarily fine phase resolution, the accessible algebra is strictly smaller than the full operator algebra. When a system becomes correlated with orthogonal environment sectors, off-diagonal operators between those sectors fall outside the accessible algebra. The reduced state is therefore indistinguishable, under all admissible operations, from its diagonal ensemble. Definiteness emerges as an algebraic consequence of sector restriction, not as a collapse postulate. The weights of these sectors are fixed uniquely by compositional consistency. Phase invariance, multiplicativity under independent refinement, and stability under record coarse-graining constrain any admissible assignment of sector weights to satisfy a functional equation whose only continuous, non-contextual solution is quadratic in amplitude. The Born rule therefore arises as the unique invariant measure compatible with finite accessibility. Irreversibility follows from action scaling: reversal requires operators outside the admissible tensor algebra and incurs action cost proportional to the number of correlated subsystems. Since admissible operations are bounded by the action gap, macroscopic record reversal is excluded. Measurement introduces no new physical primitives beyond finite accessibility, locality, and compositional stability. Record formation, classical definiteness, and Born probabilities are structural consequences of algebraic restriction under finite accessibility. **This paper is part of the Finite Accessibility series, which reconstructs gravitational geometry, quantum dynamics, gauge structure, cosmological perturbation theory, and the dark sector from a single operational primitive: a finite certification ceiling ω* governing the maximum rate at which physical relations can be maintained across extended domains.** **Introductory papers** - Geometric Limits to Coherent Timekeeping in Extended Reference Frames — https://doi.org/10.5281/zenodo.18824556 - Accessibility Selection Law (ASL) — https://doi.org/10.5281/zenodo.18824649 - Phase Boundary Gravity — https://doi.org/10.5281/zenodo.18824707 **Pillars (numbered I–IV)** - Paper I: Deriving Gravitational Geometry and Schrödinger Dynamics from Finite Accessibility — https://doi.org/10.5281/zenodo.18601600 - Paper II: Deriving Inertia, Motion, and Wave Propagation from Finite Accessibility — https://doi.org/10.5281/zenodo.18625174 - Paper III: Accessible State Spaces, Record Stability, and the Emergence of Quantum Statistics — https://doi.org/10.5281/zenodo.18625192 - Paper IV: Frame Dissolution, the Certification Ceiling, and Observable Deformations — https://doi.org/10.5281/zenodo.18654458 **Extension papers** - Dark Matter from Finite Accessibility — https://doi.org/10.5281/zenodo.18654433 - Dark Energy from Finite Accessibility — https://doi.org/10.5281/zenodo.18654523 - No-Go Theorems and the Admissibility Corridor — https://doi.org/10.5281/zenodo.18654493 - Gauge Structure from Finite Accessibility — https://doi.org/10.5281/zenodo.18928152 - Perturbation Theory from Finite Accessibility — https://doi.org/10.5281/zenodo.18928213 **Experimental paper** - Experimental Probes of Finite Accessibility: GW Dispersion and Vacuum Path Independence — https://doi.org/10.5281/zenodo.18931126 **Keywords:** Born rule derivation, measurement problem, quantum statistics, finite accessibility, operator subalgebra, record formation, definiteness emergence, wave function collapse, compositional consistency, accessible state spaces, action gap, irreversibility, sector restriction, quantum foundations, algebraic quantum mechanics, decoherence
Questions about quantum measurement are often collected under the umbrella term “the measurement problem,” which conflates record-bearing structure, fine-event actuality, and statistical weighting into a single explanatory task. This paper separates those roles through a reduction–reconstruction strategy with two structural results. First, Born weighting is suspended and the physically defined record architecture is maximally coarse-grained to the distinction between non‑record‑bearing and record‑bearing sectors. After an ideal measurement interaction, the final state may lie entirely in the record-bearing sector, establishing sharp coarse record-sector support without selecting any fine-grained event. Restoring physically meaningful record resolution preserves that coarse truth while enlarging the represented question space: whenever the same postmeasurement state has support in more than one distinguishable fine sector, no occupied fine sector contains the global state. The single-event question therefore appears not through failure of coarse dynamics, but through successful coarse dynamics followed by finer physical resolution. Second, the paper asks what could genuinely supply the missing fine-event specification. Relative to a theory‑relative completed standard-description map D̄, a deterministic actuality map X̄ is already determined by the completed description exactly when X̄ = G ∘ D̄ for some G. Non‑injectivity of D̄ alone is insufficient for actuality underdetermination; the decisive obstruction is variation of X̄ within a fiber. Failure of factorization signals the need for residual run‑level information beyond the completed standard description, whereas factorization eliminates that informational need without implying that the candidate law G is part of standard quantum theory. Stochastic completions may instead add an independently specified law of event occurrence. Probability is then restored as an empirical reconstruction constraint: admissible completions must recover the Born distribution, preserve cross‑resolution consistency, and, where applicable, reproduce protocol‑level registered‑history laws. The result is a structural separation among record‑sector support, fine‑event actuality, Born weighting, and registration, without selecting a preferred interpretation or proposing an actuality mechanism. This is version 1.0 of the manuscript.
The preferred-basis problem and the definite-outcome aspect of the measurement problem persist even when the detector is modeled unitarily. Experimental data are represented in a Boolean event algebra of mutually exclusive records, while the theoretical description employs a noncommutative operator algebra with continuous unitary symmetry. This change of mathematical structure constitutes the core of the ``cut'': a necessary interface from group-based kinematics to set-based counting. In the Operationally Induced Preferred Basis (OIPB) framework, the basis relevant for recorded outcomes is not fixed by the system Hamiltonian but induced by the measurement interface -- the detector channel together with its coarse-grained readout. The Born rule follows from Gleason-type uniqueness (Gleason for projections in d>2 and Busch's extension for POVMs including d=2), as the unique probability measure consistent with additivity over exclusive events and basis-independence of the unitary sector. A compact qubit-pointer model yields an induced unsharp POVM E±=21(1±ησz) with sharpness η fixed by pointer resolution, explicitly demonstrating detector-induced basis selection. OIPB aligns with decoherence and operational theories while diverging from collapse models (no spontaneous reductions) and the Many-Worlds Interpretation (no ontological branching). Empirical distinctions arise through POVM tomography, Wigner-friend incompatibility tests, and superposition stability bounds. Nested-observer paradoxes are resolved by a non-composability lemma: joint assignment of outcome propositions is possible only if a joint instrument exists. This relocates the origin of randomness to the stochasticity of the interface rules.
The same position need not imply the same future: observing an address may discard information about past events, active memory, and records. This work determines the data needed to reconstruct a temporal law and reconcile its spatial, coherent, and record readouts. Admissible extensions of a history define a graded generator of actualization; marked event rates specify its dynamics in physical time. We establish separate criteria for recovering the event count from an address and for the predictive sufficiency of that address. A distinguishing future test yields a sharp lower bound on the error of a purely spatial description. On a finite strongly connected state space, marked cycle probabilities classify strictly positive laws up to local changes of clock. For factorized first-event records, outcome fractions form a complete metric invariant after a common reparametrization of age has been factored out. On a finite irreducible state space, zero configurational entropy production characterizes the unitary continuation of the same temporal form. Its invariant complex sectors realize all finite-dimensional autonomous Hamiltonian dynamics, up to a global phase. Preparation, probabilistic readout, and retention of a sector require separate operational conditions. The zero-support condition for address jumps acquires the precise meaning of preserving the admissible state space, provided that the continuous evolution is also checked. For a phase-pure QND writer, an independently calibrated rate of record discrimination predicts transition suppression and a sufficient event-count budget on a finite interval. The joint pressure of transport and recording distinguishes realizations with identical separate marginals. Marked irreversibility may persist even when the configurational dynamics is reversible. These results define a testable sequence: reconstruct the event law, determine its sufficient readouts, and compare predictions across instruments. Equilibrium event algebras, protected phase constructions, and local clocks for infinite systems extend this sequence under explicitly stated assumptions. This preprint develops the temporal sector of the Theory of Structural Articulation (TSA).