Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2603.26826

Non-Relativistic Quantum Mechanics in Multidimensional Geometric Frameworks

Dalaver H. Anjum, Shahid Nawaz, Muhammad Saleem

quant-phSubmitted Mar 27, 2026• Announced Mar 30, 2026
v1 · Mar 27, 2026v2 · Apr 4, 2026v3 · Apr 14, 2026v4 · Apr 23, 2026
arXivHTMLPDF

Abstract

A generalized formulation of non-relativistic quantum mechanics is developed within multidimensional geometric (NG) frameworks characterized by a power-law dispersion relation \(E \propto |p|^{j}\), where \(j = N - 1\). Starting from the generalized Minkowski distance in \(L^j\)-normed spaces, the conventional quadratic kinetic structure of three-dimensional geometry is extended to higher-order spatial derivatives, yielding a consistent \(j\)-th order Schrödinger equation. The formalism is applied to free particles and to particles confined within a one-dimensional infinite potential well for 2G, 3G, 4G, and 5G geometries. While plane-wave solutions and translational invariance are preserved, the spectral structure is modified, with bound-state energies scaling as \((2n+1)^{j}\), leading to cubic and quartic growth in higher geometries. The corresponding eigenfunctions exhibit mixed exponential, trigonometric, and hyperbolic forms determined by the roots of negative unity. A generalized probability framework based on \(j\)-fold conjugation is introduced, ensuring a real-valued probability density and consistent expectation values. Despite these generalizations, the Heisenberg uncertainty principle is preserved. The formulation presents quantum mechanics as a geometry-dependent theory in which dispersion relations, spectral properties, and probabilistic structure emerge from the underlying spatial metric.

Comments
20 pages, 1 figure,

Related papers

A Spectral-Geometric Formulation of Extended Uncertainty Principles in Quantum Mechanics

Bholanath Padhy, Bk Majhi, K. Navya +1 more

The Heisenberg uncertainty principle is foundational to quantum mechanics, yet its standard formulation is limited to Hilbert space operator commutators. Recent advances in noncommutative geometry (NCG) allow a reformulation of quantum observables and spacetime itself using operator algebras, providing a deeper framework for uncertainty relations. In this paper, we develop a generalized uncertainty relation using spectral triples, extending the Robertson– Schrödinger inequality into the noncommutative regime. Explicit derivations are given for operator-valued distances, modified commutators, and position–momentum operators in a noncommutative configuration space. Our results reveal the emergence of a minimal measurable length scale, consistent with predictions from quantum gravity, and demonstrate that uncertainty is fundamentally geometric in origin.

East European Journal of Physics•Mar 14, 2026•0 citations

Geometric structure of the relativistic quantum phase space

Philippe Manjakasoa Randriantsoa, Ravo Tokiniaina Ranaivoson, Raoelina Andriambololona +3 more

The quest to reconcile quantum mechanics with gravitational theory motivates the exploration of frameworks that treat quantum uncertainty and spacetime geometry under a unified approach. A promising candidate that emerges from this pursuit is the relativistic quantum phase space (QPS) formalism, which extends classical phase space by incorporating both mean values and variance-covariance matrices of quantum states, providing a unified setting where the uncertainty principle and relativistic covariance coexist. For the signature $(1,4)$, we construct a scalar from the mean values and the inverse variance-covariance matrix and prove its invariance under linear canonical transformations (LCTs). Motivated by the form of the variance-covariance matrix in a particular reference frame, we identify this invariant as $Γ= L^2/\ell^2$ for states that saturate the uncertainty relations, where $L$ and $\ell$ are two fundamental length scales that can be identified with the de Sitter radius and the Planck length, respectively. From this invariant, we obtain a geometric equation that unifies mean values and quantum fluctuations. In the limit $\ell \to 0$, the equation reduces to the de Sitter spacetime equation; in the limit $L \to \infty$, it yields a curved momentum space reminiscent of Born reciprocity. In the Minkowski limit (both $\ell \to 0$ and $L \to \infty$), the familiar relativistic relations for rest mass and proper time emerge. These limiting cases show how the Planck length and the cosmological constant can be unified within a single geometric constraint, establishing the QPS geometry as a promising framework for exploring the interplay between quantum mechanics and gravity.

quant-pharXiv:2603.28836•Mar 31, 2026

C3-Phase Formalism and the Generalized Schrödinger Geometry

AKTAŞ, BORA

Abstract The present work develops a self-consistent quantum framework based on the algebraC3={1,j,j2∣j3=−1}C_{3} = \{1, j, j^{2} \mid j^{3} = -1\}C3={1,j,j2∣j3=−1}, in which the conventional Schrödinger dynamics, the probabilistic interpretation, and the space–time metric emerge from a single cyclic phase geometry. In this construction the wavefunctionψ=a+jb+j2c\psi = a + jb + j^{2}cψ=a+jb+j2cis not a mere three-component field but the cyclic sum of quantities that are mutually related through a derivative chain: aaa corresponds to configuration, bbb to temporal rate (phase velocity), and ccc to spatial curvature. The differential operator DDD acting as Dψ=jψD\psi = j\psiDψ=jψ closes as D3=−1D^{3} = -1D3=−1, producing the canonical cubic wave equation (D3+1)ψ=0.(D^{3} + 1)\psi = 0.(D3+1)ψ=0. The physical norm is defined by the real trace of the C3C_{3}C3 inner product, ∥ψ∥phys2=a2+b2+c2,\|\psi\|^{2}_{\mathrm{phys}} = a^{2} + b^{2} + c^{2},∥ψ∥phys2=a2+b2+c2, which remains positive definite and conserved under the first-order evolution j ∂tψ+j2κ∇2ψ+(ω0+V)ψ=0.j\,\partial_{t}\psi + j^{2}\kappa\nabla^{2}\psi + (\omega_{0} + V)\psi = 0.j∂tψ+j2κ∇2ψ+(ω0+V)ψ=0. This equation generalizes Schrödinger dynamics by embedding both time and spatial propagation in the derivative cycle generated by jjj and j2j^{2}j2. Its plane-wave solutions satisfy a cubic dispersion relation Ω3=κ3k6+ω03+3κω0k2,\Omega^{3} = \kappa^{3}k^{6} + \omega_{0}^{3} + 3\kappa\omega_{0}k^{2},Ω3=κ3k6+ω03+3κω0k2, which reduces to the standard quadratic form in the weak-phase limit but reveals a new E∝k2/3E \propto k^{2/3}E∝k2/3 regime at strong curvature. Hence, the classical and quantum regimes appear as two asymptotic sectors of the same geometric equation. Hermiticity, measurement, and probability are reformulated within the C3C_{3}C3-Hilbert space: an operator A^=A0+(j−j2)Avis+(j+j2)Ahid\hat{A} = A_{0} + (j - j^{2})A_{\mathrm{vis}} + (j + j^{2})A_{\mathrm{hid}}A^=A0+(j−j2)Avis+(j+j2)Ahid is C3C_{3}C3-Hermitian if ⟨ψ∣A^ϕ⟩3=⟨A^ψ∣ϕ⟩3.\langle \psi | \hat{A}\phi \rangle_{3} = \langle \hat{A}\psi | \phi \rangle_{3}.⟨ψ∣A^ϕ⟩3=⟨A^ψ∣ϕ⟩3. The visible channel j−j2j - j^{2}j−j2 encodes measurable phase differences (time–space curvature contrast), whereas the hidden channel j+j2j + j^{2}j+j2 contains the unobservable but dynamically effective phase sum. The probability measure is then derived from the real projection of the C3C_{3}C3 inner product, ensuring consistency with classical Born statistics in the b,c→0b, c \to 0b,c→0 limit. From the composite fields (a,b,c)(a, b, c)(a,b,c) one can further define emergent metric components N,Ni,γijN, N^{i}, \gamma_{ij}N,Ni,γij, yielding a 3+13+13+1 line element ds2=−N2dt2+γij(dxi+Nidt)(dxj+Njdt),ds^{2} = -N^{2}dt^{2} + \gamma_{ij}(dx^{i} + N^{i}dt)(dx^{j} + N^{j}dt),ds2=−N2dt2+γij(dxi+Nidt)(dxj+Njdt), where temporal lapse and spatial conformal factors follow directly from the visible and hidden curvature densities. Consequently, both the wave dynamics and the geometry of space–time arise from the same algebraic phase structure. The model closes the long-standing gap between the probabilistic and geometric foundations of quantum mechanics by replacing the external metric with an intrinsic C3C_{3}C3 phase metric. Potential experimental probes—such as triple-path interferometry or Ramsey-3 schemes—could isolate the predicted E∼k2/3E \sim k^{2/3}E∼k2/3 dispersion and the visible/hidden phase channels. This formulation provides a unified description in which quantum behavior, the time operator, and curvature are facets of a single cyclic geometry. It offers a mathematically closed, physically interpretable, and experimentally testable framework that extends the Schrödinger equation into the C3C_{3}C3 algebraic domain, opening a possible path toward higher-order phase systems C4,C5,C6C_{4}, C_{5}, C_{6}C4,C5,C6 and the full geometric hierarchy of multicarrier quantum dynamics.

•Nov 23, 2025•0 citations

Non-relativistic quantum mechanics

G. E. Hahne

The nonrelativistic Schrödinger equation for motion of a structureless particle in four-dimensional space-time entails a well-known expression for the conserved four-vector field of local probability density and current that are associated with a quantum state solution to the equation.Under the physical assumption that each spatial, as well as the temporal, component of this current is observable, the position in time becomes an operator and an observable in that the weighted average value of the time of the particle's crossing of a complete hyperplane can be simply defined: the theory predicts, and experiment is presumed to be able to observe, the integral over the hyperplane of the normal component of probability current, weighted by the time coordinate.In conventional formulations the hyperplane is always spacelike, i.e., is a time=constant hyperplane in Galilean relativity, and the result is then trivial.A nontrivial result is obtained if the plane is not of this type.When the space-time coordinates are (t, x, y, z), the paper analyzes in detail the case that the hyperplane is of the type z=constant.Particles can cross such a hyperplane in either direction, so it proves convenient to introduce an indefinite metric, and correspondingly a sesquilinear inner product with non-Hilbert space structure, for the space of quantum states on such a surface.Since the metric is indefinite, an uncertainty principle involving the dispersion of the crossing time and the dispersion of its conjugate momentum does not appear to be derivable from the theory.A detailed formalism for computing average crossing times on a z=constant hyperplane, and average dwell times and delay times for a zone of interaction contained between a pair of z=constant hyperplanes, is presented.

Institute of Physics eBooks•Nov 26, 2004•2 citations

A Probabilistic–Geometric Unification of Relativistic and Quantum Dynamics Information Curvature as a Common Structural Equation

Ryusho Nemoto

The absence of a common mathematical structure underlying quantum theory and relativistic physics remains a central obstacle to unification. While relativity is formulated in terms of spacetime geometry and covariance, quantum theory is intrinsically probabilistic, relying on amplitudes, uncertainty, and statistical interpretation. Existing unification programs typically attempt to quantize geometry or to geometrize quantum fields, but the probabilistic structure itself is rarely treated as a fundamental geometric object. In this paper, we propose a unified description of relativistic and quantum dynamics based on probabilistic geometry. Probability densities are taken as primary variables and are endowed with an intrinsic information–geometric structure defined by the Fisher–Rao metric. Within this framework, physical motion is described as the covariant evolution of probability distributions on a statistical manifold rather than as trajectories in a preassigned phase space or Hilbert space. The central result is a unified probabilistic–geometric field equation in which the relativistic d’Alembertian acting on the probability density is coupled to the scalar curvature of the associated information manifold. In an appropriate nonrelativistic limit, this equation reproduces the quantum potential as a curvature term, establishing a direct correspondence between quantum effects and informational geometry. Relativistic covariance is preserved throughout, allowing quantum and relativistic structures to appear as different regimes of a single probabilistic equation. The proposed framework does not introduce new particles, interactions, or quantization postulates. Instead, it provides a structural unification in which quantum and relativistic features emerge from the geometry of probability itself.

•Feb 20, 2026•0 citations

Quantum Mechanics from Five-Dimensional Spacetime: A Geometric Origin of Probability

Kisida, Shota

We demonstrate that quantum mechanics emerges naturally from the five-dimensional hydrodynamic spacetime framework. The central insight is that quantum probability arises not from fundamental indeterminacy but from observers' confinement to three spatial dimensions. An observer measuring a particle's position integrates over all possible values of the fourth spatial coordinate w (the time density dimension), creating an apparent probability distribution even for particles with definite five-dimensional positions. Starting from the classical geodesic equations in five-dimensional spacetime, we derive the Schrödinger equation through dimensional projection and the assumption of w-confinement at the scale Δw ~ ℏ/(mc). The Planck constant ℏ emerges as a geometric quantity setting the width of the observational window in the w-direction. We show that Heisenberg's uncertainty principle, wave-particle duality, quantum tunneling, and entanglement all follow from the five-dimensional geometric structure without additional postulates. The theory makes a striking prediction: particles should possess excited states in the w-direction with masses m_n = (2n+1)m₀, where m₀ is the ground state mass and n = 0,1,2,... For electrons, this predicts states at 1.53 MeV/c², 2.56 MeV/c², and higher energies. Searches for these resonances in high-energy collisions provide direct experimental tests of the geometric origin of quantum mechanics. This work resolves the measurement problem by showing that wavefunction collapse is the process of dimensional projection from five to three dimensions, constrained by the observer's limited w-resolution. Quantum mechanics is thus revealed as the statistical mechanics of observers confined to lower-dimensional hypersurfaces within a deterministic five-dimensional spacetime. This is the second paper of a trilogy. The foundational framework is developed in "Five-Dimensional Hydrodynamic Spacetime: Time Density and Dark Energy Complementarity." Dark matter implications are addressed in "Dark Matter as Temporal Displacement in Five-Dimensional Hydrodynamic Spacetime."

•Dec 13, 2025•0 citations
A generalized formulation of non-relativistic quantum mechanics is developed within multidimensional geometric (NG) frameworks characterized by a power-law dispersion relation (E \propto |p|^{j}), where (j = N - 1). Starting from the generalized Minkowski distance in (L^j)-normed spaces, the conventional quadratic kinetic structure of three-dimensional geometry is extended to higher-order spatial derivatives, yielding a consistent (j)-th order Schrödinger equation. The formalism is applied to free particles and to particles confined within a one-dimensional infinite potential well for 2G, 3G, 4G, and 5G geometries. While plane-wave solutions and translational invariance are preserved, the spectral structure is modified, with bound-state energies scaling as ((2n+1)^{j}), leading to cubic and quartic growth in higher geometries. The corresponding eigenfunctions exhibit mixed exponential, trigonometric, and hyperbolic forms determined by the roots of negative unity. A generalized probability framework based on (j)-fold conjugation is introduced, ensuring a real-valued probability density and consistent expectation values. Despite these generalizations, the Heisenberg uncertainty principle is preserved. The formulation presents quantum mechanics as a geometry-dependent theory in which dispersion relations, spectral properties, and probabilistic structure emerge from the underlying spatial metric.
The Heisenberg uncertainty principle is foundational to quantum mechanics, yet its standard formulation is limited to Hilbert space operator commutators. Recent advances in noncommutative geometry (NCG) allow a reformulation of quantum observables and spacetime itself using operator algebras, providing a deeper framework for uncertainty relations. In this paper, we develop a generalized uncertainty relation using spectral triples, extending the Robertson– Schrödinger inequality into the noncommutative regime. Explicit derivations are given for operator-valued distances, modified commutators, and position–momentum operators in a noncommutative configuration space. Our results reveal the emergence of a minimal measurable length scale, consistent with predictions from quantum gravity, and demonstrate that uncertainty is fundamentally geometric in origin.
The quest to reconcile quantum mechanics with gravitational theory motivates the exploration of frameworks that treat quantum uncertainty and spacetime geometry under a unified approach. A promising candidate that emerges from this pursuit is the relativistic quantum phase space (QPS) formalism, which extends classical phase space by incorporating both mean values and variance-covariance matrices of quantum states, providing a unified setting where the uncertainty principle and relativistic covariance coexist. For the signature (1,4)(1,4)(1,4), we construct a scalar from the mean values and the inverse variance-covariance matrix and prove its invariance under linear canonical transformations (LCTs). Motivated by the form of the variance-covariance matrix in a particular reference frame, we identify this invariant as Γ=L2/ℓ2Γ= L^2/\ell^2Γ=L2/ℓ2 for states that saturate the uncertainty relations, where LLL and ℓ\ellℓ are two fundamental length scales that can be identified with the de Sitter radius and the Planck length, respectively. From this invariant, we obtain a geometric equation that unifies mean values and quantum fluctuations. In the limit ℓ→0\ell \to 0ℓ→0, the equation reduces to the de Sitter spacetime equation; in the limit L→∞L \to \inftyL→∞, it yields a curved momentum space reminiscent of Born reciprocity. In the Minkowski limit (both ℓ→0\ell \to 0ℓ→0 and L→∞L \to \inftyL→∞), the familiar relativistic relations for rest mass and proper time emerge. These limiting cases show how the Planck length and the cosmological constant can be unified within a single geometric constraint, establishing the QPS geometry as a promising framework for exploring the interplay between quantum mechanics and gravity.
Abstract The present work develops a self-consistent quantum framework based on the algebraC3={1,j,j2∣j3=−1}C_{3} = \{1, j, j^{2} \mid j^{3} = -1\}C3={1,j,j2∣j3=−1}, in which the conventional Schrödinger dynamics, the probabilistic interpretation, and the space–time metric emerge from a single cyclic phase geometry. In this construction the wavefunctionψ=a+jb+j2c\psi = a + jb + j^{2}cψ=a+jb+j2cis not a mere three-component field but the cyclic sum of quantities that are mutually related through a derivative chain: aaa corresponds to configuration, bbb to temporal rate (phase velocity), and ccc to spatial curvature. The differential operator DDD acting as Dψ=jψD\psi = j\psiDψ=jψ closes as D3=−1D^{3} = -1D3=−1, producing the canonical cubic wave equation (D3+1)ψ=0.(D^{3} + 1)\psi = 0.(D3+1)ψ=0. The physical norm is defined by the real trace of the C3C_{3}C3 inner product, ∥ψ∥phys2=a2+b2+c2,\|\psi\|^{2}_{\mathrm{phys}} = a^{2} + b^{2} + c^{2},∥ψ∥phys2=a2+b2+c2, which remains positive definite and conserved under the first-order evolution j ∂tψ+j2κ∇2ψ+(ω0+V)ψ=0.j\,\partial_{t}\psi + j^{2}\kappa\nabla^{2}\psi + (\omega_{0} + V)\psi = 0.j∂tψ+j2κ∇2ψ+(ω0+V)ψ=0. This equation generalizes Schrödinger dynamics by embedding both time and spatial propagation in the derivative cycle generated by jjj and j2j^{2}j2. Its plane-wave solutions satisfy a cubic dispersion relation Ω3=κ3k6+ω03+3κω0k2,\Omega^{3} = \kappa^{3}k^{6} + \omega_{0}^{3} + 3\kappa\omega_{0}k^{2},Ω3=κ3k6+ω03+3κω0k2, which reduces to the standard quadratic form in the weak-phase limit but reveals a new E∝k2/3E \propto k^{2/3}E∝k2/3 regime at strong curvature. Hence, the classical and quantum regimes appear as two asymptotic sectors of the same geometric equation. Hermiticity, measurement, and probability are reformulated within the C3C_{3}C3-Hilbert space: an operator A^=A0+(j−j2)Avis+(j+j2)Ahid\hat{A} = A_{0} + (j - j^{2})A_{\mathrm{vis}} + (j + j^{2})A_{\mathrm{hid}}A^=A0+(j−j2)Avis+(j+j2)Ahid is C3C_{3}C3-Hermitian if ⟨ψ∣A^ϕ⟩3=⟨A^ψ∣ϕ⟩3.\langle \psi | \hat{A}\phi \rangle_{3} = \langle \hat{A}\psi | \phi \rangle_{3}.⟨ψ∣A^ϕ⟩3=⟨A^ψ∣ϕ⟩3. The visible channel j−j2j - j^{2}j−j2 encodes measurable phase differences (time–space curvature contrast), whereas the hidden channel j+j2j + j^{2}j+j2 contains the unobservable but dynamically effective phase sum. The probability measure is then derived from the real projection of the C3C_{3}C3 inner product, ensuring consistency with classical Born statistics in the b,c→0b, c \to 0b,c→0 limit. From the composite fields (a,b,c)(a, b, c)(a,b,c) one can further define emergent metric components N,Ni,γijN, N^{i}, \gamma_{ij}N,Ni,γij, yielding a 3+13+13+1 line element ds2=−N2dt2+γij(dxi+Nidt)(dxj+Njdt),ds^{2} = -N^{2}dt^{2} + \gamma_{ij}(dx^{i} + N^{i}dt)(dx^{j} + N^{j}dt),ds2=−N2dt2+γij(dxi+Nidt)(dxj+Njdt), where temporal lapse and spatial conformal factors follow directly from the visible and hidden curvature densities. Consequently, both the wave dynamics and the geometry of space–time arise from the same algebraic phase structure. The model closes the long-standing gap between the probabilistic and geometric foundations of quantum mechanics by replacing the external metric with an intrinsic C3C_{3}C3 phase metric. Potential experimental probes—such as triple-path interferometry or Ramsey-3 schemes—could isolate the predicted E∼k2/3E \sim k^{2/3}E∼k2/3 dispersion and the visible/hidden phase channels. This formulation provides a unified description in which quantum behavior, the time operator, and curvature are facets of a single cyclic geometry. It offers a mathematically closed, physically interpretable, and experimentally testable framework that extends the Schrödinger equation into the C3C_{3}C3 algebraic domain, opening a possible path toward higher-order phase systems C4,C5,C6C_{4}, C_{5}, C_{6}C4,C5,C6 and the full geometric hierarchy of multicarrier quantum dynamics.
The nonrelativistic Schrödinger equation for motion of a structureless particle in four-dimensional space-time entails a well-known expression for the conserved four-vector field of local probability density and current that are associated with a quantum state solution to the equation.Under the physical assumption that each spatial, as well as the temporal, component of this current is observable, the position in time becomes an operator and an observable in that the weighted average value of the time of the particle's crossing of a complete hyperplane can be simply defined: the theory predicts, and experiment is presumed to be able to observe, the integral over the hyperplane of the normal component of probability current, weighted by the time coordinate.In conventional formulations the hyperplane is always spacelike, i.e., is a time=constant hyperplane in Galilean relativity, and the result is then trivial.A nontrivial result is obtained if the plane is not of this type.When the space-time coordinates are (t, x, y, z), the paper analyzes in detail the case that the hyperplane is of the type z=constant.Particles can cross such a hyperplane in either direction, so it proves convenient to introduce an indefinite metric, and correspondingly a sesquilinear inner product with non-Hilbert space structure, for the space of quantum states on such a surface.Since the metric is indefinite, an uncertainty principle involving the dispersion of the crossing time and the dispersion of its conjugate momentum does not appear to be derivable from the theory.A detailed formalism for computing average crossing times on a z=constant hyperplane, and average dwell times and delay times for a zone of interaction contained between a pair of z=constant hyperplanes, is presented.
The absence of a common mathematical structure underlying quantum theory and relativistic physics remains a central obstacle to unification. While relativity is formulated in terms of spacetime geometry and covariance, quantum theory is intrinsically probabilistic, relying on amplitudes, uncertainty, and statistical interpretation. Existing unification programs typically attempt to quantize geometry or to geometrize quantum fields, but the probabilistic structure itself is rarely treated as a fundamental geometric object. In this paper, we propose a unified description of relativistic and quantum dynamics based on probabilistic geometry. Probability densities are taken as primary variables and are endowed with an intrinsic information–geometric structure defined by the Fisher–Rao metric. Within this framework, physical motion is described as the covariant evolution of probability distributions on a statistical manifold rather than as trajectories in a preassigned phase space or Hilbert space. The central result is a unified probabilistic–geometric field equation in which the relativistic d’Alembertian acting on the probability density is coupled to the scalar curvature of the associated information manifold. In an appropriate nonrelativistic limit, this equation reproduces the quantum potential as a curvature term, establishing a direct correspondence between quantum effects and informational geometry. Relativistic covariance is preserved throughout, allowing quantum and relativistic structures to appear as different regimes of a single probabilistic equation. The proposed framework does not introduce new particles, interactions, or quantization postulates. Instead, it provides a structural unification in which quantum and relativistic features emerge from the geometry of probability itself.
We demonstrate that quantum mechanics emerges naturally from the five-dimensional hydrodynamic spacetime framework. The central insight is that quantum probability arises not from fundamental indeterminacy but from observers' confinement to three spatial dimensions. An observer measuring a particle's position integrates over all possible values of the fourth spatial coordinate w (the time density dimension), creating an apparent probability distribution even for particles with definite five-dimensional positions. Starting from the classical geodesic equations in five-dimensional spacetime, we derive the Schrödinger equation through dimensional projection and the assumption of w-confinement at the scale Δw ~ ℏ/(mc). The Planck constant ℏ emerges as a geometric quantity setting the width of the observational window in the w-direction. We show that Heisenberg's uncertainty principle, wave-particle duality, quantum tunneling, and entanglement all follow from the five-dimensional geometric structure without additional postulates. The theory makes a striking prediction: particles should possess excited states in the w-direction with masses m_n = (2n+1)m₀, where m₀ is the ground state mass and n = 0,1,2,... For electrons, this predicts states at 1.53 MeV/c², 2.56 MeV/c², and higher energies. Searches for these resonances in high-energy collisions provide direct experimental tests of the geometric origin of quantum mechanics. This work resolves the measurement problem by showing that wavefunction collapse is the process of dimensional projection from five to three dimensions, constrained by the observer's limited w-resolution. Quantum mechanics is thus revealed as the statistical mechanics of observers confined to lower-dimensional hypersurfaces within a deterministic five-dimensional spacetime. This is the second paper of a trilogy. The foundational framework is developed in "Five-Dimensional Hydrodynamic Spacetime: Time Density and Dark Energy Complementarity." Dark matter implications are addressed in "Dark Matter as Temporal Displacement in Five-Dimensional Hydrodynamic Spacetime."