This paper proposes Causal Bandwidth Reconstruction as a finite-information framework for interpreting physical reality. The central claim is that an observer-like physical system does not access the complete instantaneous state of the universe, but reconstructs an effective reality from causally available information constrained by light-speed delay, channel bandwidth, source capacity, memory, and processing limits. The paper introduces a causal bandwidth bound combining propagation delay, effective information bandwidth, source information capacity, and observer integration capacity. It then defines observer-relative effective reality as a reconstruction map acting on information from the past light cone. Within this framework, classical physical laws are interpreted as stable compression rules: position, velocity, mass, temperature, pressure, rigidity, friction, optical objects, and field values are treated as low-dimensional variables that remain stable after inaccessible microscopic distinctions are removed. The revised version adds a conditional Born-rule stabilization argument. It does not claim to derive the Born rule from light speed alone. Instead, it shows that if stable quantum records form an orthogonal event algebra and the reconstruction map is positive, normalized, additive on orthogonal channels, unitarily invariant, noncontextual, and stable under finite-bandwidth coarse-graining, then Gleason-type reasoning selects the squared Hilbert amplitude as the unique stable record probability. In this interpretation, the Born rule is treated as the probability measure naturally selected by stable finite-bandwidth record reconstruction. The paper also adds testable directions. These include finite-bandwidth delayed-choice quantum eraser experiments, bandwidth-controlled decoherence and record-stabilization studies in macroscopic quantum systems, finite-time Wigner-type record synchronization, and numerical estimates using photon-counting detector bandwidths, sensory bandwidths, and integration capacities. A curved-spacetime extension is outlined by replacing the flat delay r/c with retarded causal time in a general metric and by interpreting horizons as extreme causal-bandwidth boundaries. This work is theoretical and interpretive. It does not replace standard quantum mechanics, relativity, thermodynamics, or statistical mechanics. Rather, it provides a unifying finite-information lens through which classical laws, thermodynamic coarse-graining, optical perception, field descriptions, quantum measurement, Born-rule stabilization, and observer-relative record formation can be understood as different regimes of causal information reconstruction. Interdisciplinary fields crossed by this work include theoretical physics, special relativity, quantum foundations, Born-rule studies, decoherence theory, quantum measurement theory, information theory, Shannon communication theory, statistical mechanics, thermodynamics, black-hole information theory, holographic principle research, philosophy of physics, information geometry, cognitive science of observation, artificial observer theory, AI systems, virtual embodiment studies, and complex-systems modeling.
We develop a conditionally closed reconstruction of quantum mechanics from exactly three physical axioms: microscopic ontic definiteness and finite localization, physical reality of the spacetime--vacuum substrate, and persistent causal source--response coupling. Wave functions, Hilbert spaces, complex amplitudes, density operators, the Born rule, commutation relations, Fock spaces, path integrals, completely positive maps, and Markovian dynamics are introduced only as derived mathematical or operational structures, not as additional physical axioms. The construction distinguishes the actual finite carrier and its causal history from the quantum state used to represent preparations, transformations, and measurement probabilities. It derives unitary dynamics from self-adjoint Hamiltonians, formulates spectral observables and probability currents, and states the explicit equilibrium, additivity, noncontextuality, and calibration conditions required for the Born representation. Measurement is described through instruments, pointer dynamics, stable records, weak values, continuous monitoring, diffusive and counting trajectories, and operational error--disturbance relations. Quantum trajectories remain record-conditioned predictive representations rather than automatically ontic paths. Composite systems, identical particles, spin, entanglement entropy, purification, steering, Bell correlations, dense coding, and no-broadcasting are developed on declared tensor-product and symmetry domains. Open-system dynamics are formulated through causal Volterra equations, memory kernels, initial-slip terms, auxiliary-mode realizations, and unitary dilations. Existence, positivity, complete positivity, trace preservation, no-signalling, and energy closure are treated as logically distinct properties. Semiclassical pseudodifferential calculus, controlled path-integral convergence, Ehrenfest-time bounds, semiclassical measures, decoherence, and macroscopic-record stability define the quantum--classical interface. Topological phases, defect-bound states, relativistic wave equations, infrared dressing, and effective quantum-field-theory domains are incorporated with explicit applicability and error conditions. Numerical spectral certification, statistical model comparison, twenty-five benchmark models, theorem-status ledgers, and a complete experimental statistical protocol provide falsification and replication criteria. The resulting framework preserves standard quantum mechanics on its validated domain while isolating finite-core and historical corrections as conditional, quantitatively bounded, and experimentally testable extensions. **Keywords** Quantum foundations; topological quantum mechanics; historical memory; three-axiom reconstruction; Born rule; quantum measurement; weak measurement; quantum trajectories; entanglement; spin and statistics; open quantum systems; Volterra equations; semiclassical limit; quantum topology; numerical certification; experimental falsification.
Quantum mechanics lacks a physical definition of measurement, observer, probability, and experienced time. These notions are instead treated as primitive or interpretation-dependent, leading to persistent foundational problems including the measurement problem, the origin of the Born rule, observer disagreement in Wigner’s Friend scenarios, the arrow of time, and apparent information loss in black hole evaporation. In this work, we show that these problems share a single missing ingredient: the absence of an operational definition of observers as bounded physical systems. We define observers as physically realizable systems capable of forming irreversible internal records under unitary dynamics. Measurement is identified with record formation, probability with record redundancy, experienced time with record accumulation, and irreversibility with computational inaccessibility rather than non-unitarity. Using decoherence and quantum Darwinism, we show that the number of accessible, decoherence-stable records associated with an outcome scales with the squared amplitude, yielding the Born rule from record counting without invoking collapse, subjective probability, or additional axioms. Observer-relative paradoxes dissolve once outcome definiteness is indexed to record formation rather than to the global quantum state. Reconstruction of global quantum information is shown to require exponential resources, rendering measurement and black hole evaporation operationally irreversible despite global unitarity. The resulting framework closes quantum mechanics conceptually by eliminating undefined primitives, without modifying its mathematical structure or introducing new dynamical postulates.
This work establishes a minimal, physically grounded definition of an observer—finite, local, interaction-driven, and relational—and shows that from these conditions alone, the core structures of physics necessarily follow. Quantum mechanics (Hilbert space, linearity, Born rule, no-cloning, uncertainty), thermodynamics (the second law, Landauer’s principle), and relativistic causality (finite invariant propagation speed) are not postulated but emerge as unavoidable consequences of what it means for a system to record interactions. The result is a single constraint: any universe capable of containing such observers must exhibit these structures and properties, including non-equilibrium conditions, stable bound states, finite signal speed, and a compatible spacetime dimensionality. Physics, in this framework, is not a collection of independent laws but the unique coherent description of observer-compatible reality.
This paper formulates the Relational Recoverable Reality Principle, a strengthened extension of the Recoverable Reality Principle in which physical realization is described as observer-relative recoverable compression rather than as a single global description of reality. The framework replaces a universal compression map with relational compression maps between interacting subsystems. A physical state is treated as realized when it can be compressed into an effective description, reconstructed up to the equivalence class accessible to a reference subsystem, and protected against singular, nonregular, or information-erasing failure modes. The paper introduces coarse-grained information-geometric reconstruction distances, running recovery couplings, an emergent-time construction from recursive realization events, and sector templates for quantum measurement, gravitational geometry, black-hole horizons, cosmology, and numerical graph-based implementation. In the quantum sector, Born weights are interpreted as minimally lossy measurement records under recoverable compression. In the gravitational sector, smooth geometry is treated as an effective compression of relational substrate data, while singularities are interpreted as nonrecoverable boundary failures. The resulting theory is presented as a relational, computable, and empirically oriented architecture for studying physical realization, rather than as a final microscopic theory of all sectors.
This paper develops a conditional first-principles architecture for reconstructing the Born rule from delayed recoverable geometry and recoverability–fidelity rigidity. The framework is organized in two layers. The first layer, Delayed Recoverable Geometry Completion, begins from stabilized distinction, delayed history, closure-defect suppression, and recoverable compression rather than from primitive spacetime, instantaneous time evolution, or measurement probability. Within this layer, physical realization is treated as a stable and observer-relative recoverable compression of deeper relational structure. The second layer, Recoverability–Fidelity Rigidity under Unitary Retarded Probability Dynamics, reconstructs the Born rule inside the projective quantum sector. Instead of postulating an additive probability measure over projectors, the theory introduces a recoverability functional between physical rays. Ray invariance, unitary covariance, orthogonality annihilation, tensor multiplicativity, and local ray-reconstruction calibration force this recoverability functional to become squared projective fidelity. Stable record cells then generate branch projectors, branch recoverability becomes the standard Born weight, and large-record frequency stabilization converts these weights into observed probabilities. A revised ray-quotient reconstruction loss is introduced to clarify that the quadratic exponent is fixed by intrinsic projective reconstruction error rather than by assuming the Born probability rule. The paper also includes a kernel-deformed decoherence example, showing how a delayed memory kernel can produce a concrete visibility-suppression prediction relative to ideal pure-state Born predictions while preserving the trace rule for the effective delayed state. The result is not presented as an unconditional derivation of all physics from no assumptions. Rather, it is a closed conditional architecture showing that, once delayed recoverable physical realization compresses into a reversible projective quantum sector, the Born rule can be reconstructed as the stable frequency law of recoverable quantum branches.
We reconstruct nonrelativistic quantum mechanics from exactly three physical axioms: microscopic ontic definiteness and finite localization, physical reality of the spacetime-vacuum substrate, and persistent causal source–response coupling. The single-run physical state is a finite topological core, its actual causal history, the substrate state, its sector, and the associated historical disturbance. A wave function is not identified with that ontic tuple. It is a ray in a Hilbert representation of admissible preparations and response amplitudes; a density operator is a statistical or reduced representation; and a record is a stable macroscopic event. The logical construction is acyclic. Finite-energy sector spaces and their continuous symmetry representations lead, under explicit representation conditions, to a complex Hilbert direct sum. A closed semibounded quadratic form defines the Hamiltonian and its self-adjoint realization. The standard Schrödinger action, unitary propagation, probability current, spectral observables, uncertainty relations, composite-system tensor products, spin representations, exchange sectors, instruments, and completely positive open dynamics then follow on their declared domains. Gleason-type reasoning fixes the Born form only after additivity, noncontextuality, continuity, and preparation–detector calibration are stated. Those operational conditions are not hidden physical axioms. The distribution of unresolved ontic initial data that realizes quantum equilibrium remains a realization certificate, not a theorem of topology alone. The Heisenberg representation is derived as a controlled transport of observables after Hilbert space and the self-adjoint generator have been constructed. Strongly continuous time translation, two-parameter nonautonomous propagation, common-domain Heisenberg equations, spectral matrix mechanics, regular Weyl relations, open-system adjoints, and instrument effects are connected by one certificate. Schrödinger and Heisenberg predictions are proved equivalent for one-time and finite instrument records, while finite-core, historical, truncation, domain, and detector errors remain separately bounded. Three frozen matrix benchmarks verify low-energy oscillator truncation and its state-weighted CCR defect, second-order unitary convergence for a driven doublet, Schrödinger–Heisenberg equality for a sequential instrument, finite auxiliary-history truncation, and quadratic leakage scaling for a conditional Dirac–Pauli interface. Independent reproduction, including the extended-precision audit, is closed for the frozen packet; physical coefficient calibration remains open. The next interface connects an owner-resolved Dirac–Pauli Hamiltonian to spin records through a Ward-compatible vertex, a causal passive history kernel, an independently audited doublet projection, SPAM-aware forward probabilities, nuisance-profiled identifiability, and a noncompensatory coefficient-to-record error theorem. The DPHC identifiability coordinate is executed on a frozen synthetic response family. A single-scale design is rank deficient, whereas an eighteen-setting frequency–gradient–order–time design has full profiled rank, controlled conditioning, near-nominal finite-sample coverage, and a calibrated held-out statistic. A robust twenty-setting design raises the worst registered information eigenvalue by
20.12%. A ten-parameter nonlinear audit exhibits an exact radiative–detector equivalence curve. An independent dark record breaks that symmetry and restores full local rank. Continuous-set robustness, validated global exclusion, and independent implementation are executed, while physical response identification and empirical calibration remain open. Measurement is treated as a dynamics of system, apparatus, environment, and actual history. Unitary premeasurement and decoherence select robust record sectors but do not by themselves select one record. The three-axiom ontology supplies one actual branch history, while a measurable response map from the complete initial state and instrument to the final record supplies the missing dynamical content. Bell correlations require contextual and nonfactorizable ontic response while parameter independence and operational no-signalling are retained; no controllable superluminal channel is introduced. Historical response produces causal non-Markov Hamiltonians and memory-kernel master equations. Their normalization, positivity, complete positivity, and energy ledger are derived from a unitary enlarged realization whenever such a dilation exists. Finite-core form factors and causal memory yield explicit departures from point-core Markov quantum mechanics. Standard quantum mechanics is recovered as the unresolved-core, sector-fixed, quantum-equilibrium, short-memory limit. Quantum field theory is retained as a successful local, spectral, and asymptotic calculus, but field operators, Fock vectors, and vacuum functionals remain effective representations until a noncircular map from finite carriers and their complete causal histories has been certified. The manuscript proves a sequence of previously open analytic, mathematical, measurement, topological, statistical, and computational obligations on explicitly declared domains. These include non-Markov diffusion, graph-norm stability, distorted-wave and pole variation, finite passive-memory realization, Fisher-information identifiability, detector pushforwards, unique-record basins, Born-representation bounds, measurement independence, topology–Dirac charge conjugation, Stern–Gerlach records, action-scale matching, rank-two spin projection, Finkelstein–Rubinstein topology, Clifford reconstruction, and parent-to-record realization maps. Eighteen groups of numerical obligations are executed on frozen reference models. They cover spectral and scattering calculations, oscillator and two-level dynamics, Schrödinger–Heisenberg equivalence, finite-history truncation, Dirac–Pauli and Foldy–Wouthuysen reduction, gauge covariance, interference, Bell and GHZ correlations, open-system memory, Stern–Gerlach records, identifiability, global searches, topological invariants, path products, semiclassical limits, partial-wave optical closure, the relativistic/QFT interface, and conservative-parent two-level dynamics. Every environment explicitly typed as a computational obligation now has an executed frozen-model certificate; empirical identification and separately typed experimental inputs remain open. The present manuscript differs so substantially from the earlier version in scope, logical architecture, proofs, and executable certificates that it is issued as a new upload rather than as a minor revision. Because the subject is both foundational and technically consequential, readers professionally engaged in quantum foundations, mathematical physics, quantum measurement, or related fields are encouraged to consult both versions: the earlier version preserves the developmental route, whereas the present version gives the substantially expanded and reorganized reconstruction. ## Keywords Axiomatic quantum mechanics; finite particle histories; retarded Green functions; Schrödinger equation; Dirac equation; Born rule; topological spin; quantum measurement; non-Markovian dynamics; classical limit.