In the FIGID framework (Field Intrinsic Gravity Induced Density), mass is condensed quantum field and gravity is a density gradient. This paper extends the framework to quantum interference, decoherence, and the quantum eraser. A particle in superposition is described as a single coherent field configuration extended across multiple paths, with interference encoded in the field density itself before any measurement occurs. The field amplitude at a point is the coherent sum of Yukawa-sourced contributions from each path, and the detection probability is proportional to the squared magnitude of that amplitude. When a which-path probe interacts with the configuration at one path, the probe’s field creates an asymmetric gradient that entangles the particle’s configuration with the probe’s state. The interference term transfers from the particle alone into the joint particle-probe field configuration. Tracing over the probe eliminates the cross term from the particle’s reduced state — decoherence. The quantum eraser is then shown to recover the interference by applying a symmetric transformation to the probe that erases path information, restoring the cross term in conditioned subsets. The entire sequence is presented in both standard quantum formalism and FIGID field language side by side. A visibility function V(η) = exp(−d/λ) is derived from the physical overlap of the probe’s field configuration with the particle’s two-path superposition, reproducing the observed wavelength dependence of decoherence and providing a physical mechanism absent from the standard account. The central claim is falsifiable: if coherence were destroyed rather than redistributed, the quantum eraser would not work. It does.
In the FIGID framework (Field Intrinsic Gravity Induced Density), mass is condensed quantum field and gravity is a density gradient. This paper extends the framework to quantum interference, decoherence, and the quantum eraser. A particle in superposition is described as a single coherent field configuration extended across multiple paths, with interference encoded in the field density itself before any measurement occurs. The field amplitude at a point is the coherent sum of Yukawa-sourced contributions from each path, and the detection probability is proportional to the squared magnitude of that amplitude. When a which-path probe interacts with the configuration at one path, the probe’s field creates an asymmetric gradient that entangles the particle’s configuration with the probe’s state. The interference term transfers from the particle alone into the joint particle-probe field configuration. Tracing over the probe eliminates the cross term from the particle’s reduced state — decoherence. The quantum eraser is then shown to recover the interference by applying a symmetric transformation to the probe that erases path information, restoring the cross term in conditioned subsets. The entire sequence is presented in both standard quantum formalism and FIGID field language side by side. A visibility function V(η) = exp(−d/λ) is derived from the physical overlap of the probe’s field configuration with the particle’s two-path superposition, reproducing the observed wavelength dependence of decoherence and providing a physical mechanism absent from the standard account. The central claim is falsifiable: if coherence were destroyed rather than redistributed, the quantum eraser would not work. It does.
The quantum measurement problem has resisted resolution for nearly a century. Quantum mechanics describes particles as waves — diffuse probability distributions spread across space. Measurement appears to collapse this distribution instantaneously to a single definite location. What causes the collapse? Standard quantum mechanics provides no answer. The wavefunction evolves deterministically under the Schrödinger equation until measurement, at which point it collapses probabilistically. The transition between these two behaviors has no physical mechanism in the standard formulation. This paper proposes a physical mechanism, presented here in corrected form. Within the Field Intrinsic Gravity Induced Density (FIGID) framework, a particle is a diffuse field condensation — a region of elevated field density spread over some volume. Measurement is a two-stage physical process. In the first stage, a which-path probe couples to the condensation asymmetrically: the probe's own field ends in a distinguishably different configuration depending on which path the particle took. This coupling entangles the probe with the condensation and redistributes the particle's phase structure into the joint particle–probe field. Interference disappears from the particle's own state not because the condensation localized, but because its coherence now resides in the combined configuration. In the second stage, the condensation localizes — at final registration, when it enters the steep gradient environment of a macroscopic detector and condenses to a definite position with probability proportional to its local field density. This is wavefunction collapse, and it requires no observer. The revision from Version 1 is specific and is documented in the Version Note below. The earlier claim that a which-path detector's mass-sourced gradient forces localization at the slit is withdrawn. The quantum eraser demonstrates that coherence survives the which-path interaction — it is redistributed, not destroyed — which is impossible if localization occurred at the slit. The corrected mechanism, developed in full mathematical form in the companion paper Coherence Is a Field Configuration, replaces gradient strength with coupling asymmetry as the decoherence variable and defers localization to registration.
Quantum entanglement is usually treated as a nonlocal correlation between two particles, with no physical mechanism explaining how the shared state persists across distance. This paper develops a geometric account of entanglement within the Field Intrinsic Gravity Induced Density (FIGID) framework. When a photon enters a nonlinear crystal and undergoes parametric down-conversion, the result is not two independent particles. It is one field condensation that has been divided into two lobes of a single extended field state. These lobes remain connected through the fill-density substrate at baseline density ρ₀. The coherence of this extended state is governed not by the gradient of the fill-density field but by its roughness — the spatial variance of the gradient, which measures how rapidly the field landscape bends. This roughness is defined as a scalar quantity σ_ρ = avg(|∇δρ|²), and it determines the coherence length through an inverse-roughness law: L_c = K_lab / R_n, where R_n is the measurable refractive-index gradient roughness and K_lab is a universal constant. This law predicts that coherence length is controlled entirely by the environmental roughness of the intervening medium, producing a universal hyperbola that spans vacuum, optical fiber, and open air. The coupling constant β between fill-density and refractive index is fixed by the FIGID complementarity relation S × T = 1, giving β = ρ₀/2 with no adjustable parameters. The coherence law therefore contains only one undetermined quantity: the collapse threshold C₀. The framework provides a physical mechanism for why entangled states persist: they are one object, and the environment determines how far that object can stretch before being forced to localize. A companion paper [11] establishes that localization is driven by the gradient environment of the detector, not by pre-existing properties of the particle, ensuring compatibility with Bell’s theorem. A specific experimental prediction distinguishes this account from standard decoherence theory: active field smoothing of the intervening medium should extend entanglement range beyond what passive vacuum improvement alone achieves.
This article develops a relational interpretation of the quantum eraser experiment, showing that interference and which‑path information are not intrinsic properties of quantum systems but context‑dependent relational structures. By analyzing the experiment without invoking retrocausality or observer‑dependent collapse, the paper demonstrates that the apparent paradox arises from mixing incompatible informational frames. Interference is recovered when relational coherence is preserved, while its disappearance corresponds to a change in the network of informational relations rather than a physical erasure. The model clarifies the conceptual foundations of the quantum eraser and provides a unified account of interference, measurement, and information flow.
This work presents a unified, interpretive account of quantum interference and delayed-choice experiments that applies equally to photons and massive particles. Rather than invoking spacetime trajectories, wave–particle duality, retrocausality, or collapse postulates, the paper locates quantum interference in the coherent evolution of internal, pre-geometric degrees of freedom defined over classical spacetime. Within this framework, “which-path” questions are not merely unanswered but fundamentally ill-posed: interference arises from global coherence of an internal field subject to experimental boundary conditions, while spacetime itself remains single-valued and classical at laboratory scales. The approach reproduces all standard quantum-mechanical predictions without modification and is explicitly interpretive rather than predictive. A central result is a unified explanation of why interference occurs across disparate physical systems—photons, electrons, atoms, and molecules—while decoherence manifests through system-dependent physical mechanisms. Photons and massive particles differ in how internal coherence is lost (e.g., electromagnetic absorption versus collisional and thermal interactions), but not in the underlying principle. Delayed-choice experiments are reinterpreted without paradox: changes to the apparatus modify boundary conditions for the internal field rather than retroactively altering particle histories. By removing spacetime paths from the fundamental ontology, the framework offers a consistent, path-free account of interference, decoherence, and localized detection that preserves the empirical success of quantum mechanics while clarifying its conceptual foundations.
Abstract The phenomenon of quantum erasure has shed light on the nature of wave-particle duality and quantum complementarity. A number of quantum erasers have been realized using the far-field diffraction of photons from a Young double-slit apparatus. By marking the path of a photon using an additional degree of freedom, the usual Young interference pattern is destroyed. An appropriate measurement of the system marking the photon’s path allows one to recover the interference pattern. Here quantum erasure is considered in the context of near-field diffraction. To observe interference in the near-field requires the use of two periodic wave functions, so that the usual ‘which way’ marker then becomes a ‘which-wave function’ marker. We determine the propagation distances for which quantum erasure, or more generally the observation of interference between the two periodic wave functions, can be observed. The meaning of wave and particle-like properties in this scenario is discussed. These results could lead to quantum eraser experiments with material particles, for which interference effects are more readily observed in the near-field rather than the far-field.
The double-slit experiment is the heart of quantum mechanics, yet its standard interpretation relies on the postulate of wavefunction probability amplitude. Starting from Space Ontology, we demonstrate that interference phenomena can be entirely derived from the geometric properties of classical spatial modes, without introducing probability amplitudes. Each slit is modeled as a localized soliton solution of the spatial orientation field equation; the interference pattern arises from the linear superposition of two mode energy densities in the far field. The key discovery is that the interference visibility V is uniquely determined by the geometric entanglement entropy E_geo of the modes, satisfying V = tanh(2E_geo). Here E_geo = ln Lambda(alpha) is a function of the mode's shape parameter alpha — a Gaussian mode (alpha=2) has zero entropy and cannot interfere, while a flat mode (alpha>2) carries large coherent capacity. This theory naturally explains the which-way and quantum eraser experiments: path marking introduces a third mode that dilutes correlations via the many-body correlation reduction theorem; erasure corresponds to the decoupling of that mode. As a flagship validation, we show that the theory quantitatively accounts for the macroscopic interference of 7000-atom sodium clusters, predicting a coherence width of approximately 66 nm — confirmed by experiment. Two testable predictions are proposed: a boundary shape compression effect, and a material-dependent visibility for nanoclusters of different compositions. This work demonstrates that wave-particle duality is not a mysterious quantum feature, but a manifestation of the geometric entanglement entropy of spatial modes — the flatter the mode, the greater the coherence capacity, and the clearer the interference. This paper is the second in the first series (17 papers total) of Space Ontology.