Abstract. Why a quantum measurement yields a single outcome has remained without direct experimental access for a century, largely because the question was considered interpretation-dependent and therefore untestable. We argue that the era of error-corrected logical qubits changes this status, and we identify the specific observable that makes it testable. First, we show that the postselection intrinsic to quantum error correction absorbs any event-level anomaly: hypothetical decision dynamics (objective collapse and allied mechanisms) can only manifest, on a logical register, through changes in functional laws rather than through individual events. Exactly two observables survive this filter — the coherence decay rate of a logical Greenberger-Horne-Zeilinger (GHZ) state and the syndrome acceptance rate. Second, we show that standard quantum mechanics predicts both observables to be strictly independent of the branch-amplitude imbalance w = |α|² − |β|² of the GHZ state, for all local Markovian noise channels. Third, a systematic inventory of the published record — spanning trapped ions, neutral atoms, superconducting and photonic platforms — shows that this imbalance has never been varied in any GHZ experiment, physical or logical. The amplitude axis of measurement dynamics is therefore experimentally virgin. Fourth, we specify a null-test protocol that requires only machine time on existing hardware: parity-oscillation scans at five imbalance values on logical GHZ states of N = 16 to 94 qubits, with and without postselection, at roughly 10⁴ shots per point, reaching slope sensitivities of about 10 % of the coherence decay rate and about 1 % absolute on the acceptance rate. A measured zero slope bounds all amplitude-coupled decision dynamics at values of N never before probed; a nonzero slope would constitute the first measured deviation from standard quantum dynamics on a macroscopic entangled register. We delineate precisely what such a test can and cannot decide, including a rigorously established indiscernibility class (Everett-type, hidden-variable, and retrocausal accounts) that no experiment of this kind can separate. The protocol is offered to all interested laboratories; its cost is machine time, not development. Preprint intended for journal submission (Phys. Rev. A / PRX Quantum). Companion record to OCU-IPC V10 (same Zenodo account). The enumeration programs referenced in Appendices A and B are included in this record. Contact: Denis Bernard phyborder838@gmail.com
Abstract. Why a quantum measurement yields a single outcome has remained without direct experimental access for a century, largely because the question was considered interpretation-dependent and therefore untestable. We argue that the era of error-corrected logical qubits changes this status, and we identify the specific observable that makes it testable. First, we show that the postselection intrinsic to quantum error correction absorbs any event-level anomaly: hypothetical decision dynamics (objective collapse and allied mechanisms) can only manifest, on a logical register, through changes in functional laws rather than through individual events. Exactly two observables survive this filter — the coherence decay rate of a logical Greenberger-Horne-Zeilinger (GHZ) state and the syndrome acceptance rate. Second, we show that standard quantum mechanics predicts both observables to be strictly independent of the branch-amplitude imbalance w = |α|² − |β|² of the GHZ state, for all local Markovian noise channels. Third, a systematic inventory of the published record — spanning trapped ions, neutral atoms, superconducting and photonic platforms — shows that this imbalance has never been varied in any GHZ experiment, physical or logical. The amplitude axis of measurement dynamics is therefore experimentally virgin. Fourth, we specify a null-test protocol that requires only machine time on existing hardware: parity-oscillation scans at five imbalance values on logical GHZ states of N = 16 to 94 qubits, with and without postselection, at roughly 10⁴ shots per point, reaching slope sensitivities of about 10 % of the coherence decay rate and about 1 % absolute on the acceptance rate. A measured zero slope bounds all amplitude-coupled decision dynamics at values of N never before probed; a nonzero slope would constitute the first measured deviation from standard quantum dynamics on a macroscopic entangled register. We delineate precisely what such a test can and cannot decide, including a rigorously established indiscernibility class (Everett-type, hidden-variable, and retrocausal accounts) that no experiment of this kind can separate. The protocol is offered to all interested laboratories; its cost is machine time, not development. Preprint intended for journal submission (Phys. Rev. A / PRX Quantum). Companion record to OCU-IPC V10 (same Zenodo account). The enumeration programs referenced in Appendices A and B are included in this record. Contact: Denis Bernard phyborder838@gmail.com
This technical report develops and tests TWMSE Candidate Equation 4A, a phenomenological, threshold-activated model of observer-induced quantum collapse formulated to preserve Born weights and operational no-signalling while producing experimentally distinguishable dynamics. Candidate Equation 4A introduces a branch-sensitive Lindblad term whose activation depends on whether an operationally defined observer record exceeds a specified threshold. The report evaluates the equation’s mathematical consistency, including trace preservation, positivity, Born-weight preservation and operational no-signalling. It also examines individual stochastic trajectories, ensemble behaviour, synthetic count-level parameter recovery, statistical power and the consequences of model misspecification. A retrospective analysis is performed using published fitted GHZ decoherence-rate summaries from two superconducting-qubit studies. This is not an analysis of original laboratory shot-level data. The combined profile analysis finds no robust positive signal for Candidate Equation 4A. Instead, it establishes provisional, threshold-dependent upper limits on the additional collapse rate. Across the report’s primary threshold range of R* = 1–9, the largest pointwise one-sided 95% upper limit is approximately 7.3 × 10³ s⁻¹, while the tightest limit is approximately 3.0 × 10³ s⁻¹ at R* = 8. These are pointwise limits and do not constitute a simultaneous confidence band. The retrospective results therefore constrain but do not favour Candidate Equation 4A. Standard quantum mechanics remains sufficient to describe the analysed GHZ summaries and does so with fewer parameters. Candidate Equation 4A survives this preliminary confrontation only in the limited scientific sense that portions of its parameter space remain unexcluded. This non-exclusion is not evidence that the candidate is correct. The report consequently specifies a dedicated amplify–hold–erase experiment using matched record-forming and coherent-control circuits. The proposed test varies observer-record size, conditional record strength and dwell time while collecting count-level measurement outcomes and contemporaneous calibrations of conventional noise. The protocol is designed to distinguish a threshold-activated observer-record contribution from smooth, conventional decoherence and other experimental effects. A preregistration template, empirical-data schema and data dictionary are supplied so that the proposed experiment can be performed and analysed as an independently reproducible and falsifiable test. The accompanying ZIP archive is the complete, self-contained reproducibility package for the results reported here. It contains the code, simulation data, published GHZ rate summaries used as inputs, derived numerical outputs, documentation, software requirements and integrity checks required to reproduce the reported computational analyses and verify the packaged results. The archive contains: • the complete report in PDF, DOCX and Markdown formats;• deterministic Python reproduction scripts;• results from 500 density-matrix consistency trials;• 250,000 simulated stochastic trajectories;• 14,336 synthetic count-level circuit rows;• synthetic parameter-recovery and statistical-power results;• model-misspecification tests;• the published fitted GHZ rate summaries used in the retrospective analysis;• individual and joint GHZ profile-likelihood results;• prediction grids and report figures;• an empty 37-column template for future empirical raw data;• a data dictionary and preregistration template;• software-environment requirements and citation metadata; and• a SHA-256 manifest for package-integrity verification. The simulated trajectories and synthetic circuit counts are computational data rather than laboratory observations. The included GHZ inputs are published fitted rate summaries and are not original experimental shot counts. No new laboratory data are included, and no empirical discovery claim is made. Successful reproduction verifies that the supplied code generates the reported mathematical checks, simulations and retrospective statistical results. It does not establish that nature follows Candidate Equation 4A, demonstrate observer-induced collapse, or show that TWMSE is empirically preferred over standard quantum mechanics. The physical ideas, TWMSE framework, research direction and scientific interpretation are those of the author. Computational assistance was used for mathematical checking, simulation, statistical analysis, document preparation and reproducibility auditing. The author directed the research and accepts responsibility for the methodology, scientific claims, interpretations and conclusions. Candidate Equation 4A should therefore be understood as an explicit, internally testable and falsifiable phenomenological candidate that has passed the reported mathematical and computational consistency checks, remains compatible with the limited published summaries examined, and now requires the proposed dedicated raw-data experiment for a meaningful empirical test.
Abstract The Born rule, typically introduced as a quantum axiom, is shown to emerge as an equilibrium condition associated with modular (KMS) balance. We identify laboratory regimes where this balance can be weakly and controllably violated, and derive a universal, normalization-preserving correction to quantum measurement probabilities in the form of a modular exponential reweighting of Born amplitudes. The correction depends solely on experimentally reconstructed reduced states and outcome-resolved modular imbalance, and vanishes exactly under equilibrium, recovering the Born rule. We build a microscopic realization using standard von Neumann premeasurement, GKLS evolution of the apparatus, and projective readout, showing that the effect arises entirely within orthodox quantum mechanics without modifying unitary dynamics. The deviation leaves single-shot outcomes unchanged but induces a directed statistical bias visible only in large-N data. Locality and no-signalling hold, since in multipartite settings the correction depends only on the modular generator of the measured subsystem. We report experiments on IBM superconducting processors. First, full two-qubit Bell tomography confirms high-fidelity stabilizer correlations (E_ZZ, E_XX ≈ 0.98), validating reconstruction and establishing a Born-accurate baseline. Second, large-statistics three-qubit GHZ runs across multiple backends (ibm_fez, ibm_marrakesh, ibm_torino) show stable {000,111} sector frequencies under shot scaling, enabling extraction of preliminary modular tilt bounds. Finally, a controlled scaling study confirms 1/√N Born shot noise up to N = 20,000, while device biases remain roughly constant, establishing the metrological separation needed to detect nonequilibrium signatures. These results define a precision framework to estimate or constrain modular tilts on present-day platforms using raw (unmitigated) populations, tomography, and validated error models. They provide the first operational bounds on deviation parameters extracted from raw NISQ data in GHZ and Bell configurations, and outline a falsifiable protocol for future non-KMS driving experiments. The analysis explicitly separates statistical fluctuations from systematic bias through shot-scaling tests, enabling robust discrimination between equilibrium Born behavior and controlled nonequilibrium effects. This positions modular balance as an experimentally testable organizing principle linking quantum measurement statistics with nonequilibrium thermodynamics. Together, theory and data show that modular nonequilibrium deviations are experimentally accessible, tightly constrained, and operationally meaningful, suggesting that the Born rule may be the equilibrium shadow of a deeper thermodynamic structure in quantum theory.
A recently proposed local measurement axiom (Postulate M) replaces the instantaneous global projection of textbook quantum mechanics with branch selection triggered by completed local decoherence, while a companion ψ-ontic analysis identifies continuous spontaneous localization (CSL) as a concrete local mechanism for the selection itself. Here we test this two-stage account quantitatively in the Einstein–Podolsky–Rosen (EPR) scenario. We integrate the nonlinear CSL stochastic Schrödinger equation for an entangled spin pair in which one particle couples to a local spin bath with random couplings, bath self-dynamics, and intra-bath interactions, while the noise field and collapse operator act only at the measurement site. Analytically, we derive an exact law for the maximal Clauser–Horne–Shimony–Holt (CHSH) value under local decoherence, Smax(t)=21+sin2(2θ)∣z(t)∣2, with z(t) the decoherence factor and θ the entanglement angle: the CHSH excess over the classical bound is consumed, never the measurement-basis probabilities, which are exactly conserved. We further show that the selection stage is governed by an exact martingale: the branch weight obeys a scalar Itô equation whose derivation requires only the orthogonality of the branches—supplied by the spin structure, not by the environment—so the Born rule emerges as an absorption probability irrespective of the residual bath coherence. Numerically, the law holds to machine precision (∼ 10−15) for all three bath classes, including interacting environments, and through finite-size recurrences; stochastic trajectories confirm Born statistics to within sampling error, with all realizations fully resolved. The ensemble-averaged reduced state of the distant particle is invariant under the local collapse-operator axis and rate—parameter independence as a structural theorem, verified to machine precision in the unitary sector—and branch amplitudes are invariant across all environmental initial conditions and dynamics (∼ 10−11), confirming that outcome randomness is not of environmental origin. In the symmetric configuration, with independent noises at both wings, the two local noises provably drive a single global branch martingale at the summed rate: selection is one joint event whose absorbing states are the correlated branches—mismatched outcomes are dynamically excluded (zero events in 300 realizations, against ∼ 25% each for a product-state control)—the joint statistics are invariant under swapping which wing completes first (93% vs 9% orderings, distributions equal within sampling error), and sampled outcomes reproduce the singlet’s measurement correlation E(β) = − cos β—with β the angle between Alice’s and Bob’s measurement axes—including a CHSH value |S| = 2.710±0.073, consistent with the Tsirelson bound 2√2 within sampling errors. Decoherence and local stochastic selection jointly reproduce the empirical content of quantum measurement in the EPR scenario with no nonlocal dynamical element: the only nonclassical resource is the nonseparability of the initial state. Nonlocal projection is thus dispensable not only axiomatically and ontologically but operationally.
The quantum formalism contains a structural discrepancy: the transition amplitude computes the interaction-specific relative phase between probe and target and its effect on coupling strength, while the post-interaction state description does not preserve it. A companion paper identified this discrepancy and argued that the measurement problem arises from mistaking the formalism’s predictive completeness for descriptive completeness at the level of individual events. The present paper develops the quantitative consequence. A minimal phenomenological model shows that, for an event-level conditional law of the stated phase-dependent form, uniform averaging over the interaction-relative phase recovers the Born rule exactly, while partial phase control narrows the outcome distribution according to a visibility-loss factor . Starting from the Jaynes-Cummings Hamiltonian for a two-level system coupled to a single-mode field, we derive the event-level conditional probability , where is the phase-coupling strength — a quantity determined by the microscopic interaction parameters. The phase-coupling strength has two contributions. A pointer-overlap term, , arises from the finite separation of the measurement pointer states and decays exponentially with measurement strength . A persistent term, , arises from beyond-dispersive corrections to the Jaynes-Cummings dynamics. The standard treatment computes the rate of these transitions by squaring the matrix elements, eliminating the relative phase between qubit and field; the present framework retains the amplitude structure prior to ensemble reduction, predicting that the transitions are phase-correlated with the qubit-field relative phase. We propose a specific experiment: sweeping measurement strength while tracking phase-resolved outcome modulation in a circuit QED system. The standard treatment predicts the modulation amplitude decays to zero; the present framework predicts it saturates at a nonzero floor. Because a small phase-dependent bias can also arise from ordinary measurement non-diagonality, the decisive evidence is not the cosine modulation itself but its parameter dependence: the predicted amplitude must scale as across controlled changes in detuning, reverse under , and persist under recalibration. The experiment is feasible with current technology and would determine whether event-level phase structure persists through the measurement interaction or is genuinely absent from the outcome-producing physics.
This manuscript presents a methods-forward, operational protocol for evaluating whether any structured dependence remains in quantum-computing measurement records after explicit modeling of standard quantum and device-level mechanisms. Classical definiteness is defined at the record layer, and pre-record states are treated as predictive descriptions rather than as classical outcome facts. Within this operational stance, the protocol converts questions about outcome status and record formation into a falsifiable test program grounded in preregistered analysis rules and standard measurement telemetry. A locked null-model family is specified in advance, incorporating standard quantum dynamics together with documented device-level mechanisms including drift, correlated and non-Markovian noise, crosstalk proxies, and leakage indicators. The framework provides operational definitions, a conservative postulate set, preregistered endpoints, residual-adjudication criteria, negative controls, a fixed windowing discipline, and a bound-first reporting standard designed to yield informative constraints under null results. Any candidate contribution beyond the declared null family must appear as structured, reproducible residual dependence that survives the locked null family and the full residual-filter sequence. Version 4.4 refines the protocol specification, clarifies evidentiary boundaries, and strengthens the integration of the synthetic demonstration. The manuscript includes a fully specified classical simulation that executes the decision pipeline under controlled conditions. The synthetic study illustrates how the protocol classifies a bounded-null case, a measured-artifact case, a partial-artifact/unresolved-covariate case, an injected structured-residual case, and a failed-topology case. This demonstration establishes computational executability of the protocol and clarifies the behavior of the decision tree, but it does not constitute empirical evidence for any physical mechanism. Because the protocol relies only on standard measurement telemetry and preregistered analysis rules, it is directly implementable across contemporary quantum-computing platforms and does not depend on any single dataset, backend, or hardware realization. The manuscript is a specification paper: it defines a reproducible evidentiary framework for record-level claims, while large-scale empirical implementation, hardware benchmarking, and cross-platform replication remain subsequent studies.
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.