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Cambridge University Press eBooks

Systems of Identical Particles

Rocco Schiavilla

Published Dec 5, 2024• 0 citations
Publisher

Abstract

Exchange and permutation operators; symmetrizer and antisymmetrizer; two bosons or two fermions in a central potential; scattering amplitudes of two identical particles in a central potential; the Fermi gas; theory of white dwarf stars; the Thomas-Fermi approximation for many-electron atoms.
DOI
10.1017/9781009473637.020

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The Pauli Exclusion Principle and the Spin-Statistics Theorem from Worldline Non-Injectivity: Exchange Phase, Rapidity, and Topological Sheet Structure

Alex De Giuseppe

The Pauli Exclusion Principle and the Spin-Statistics Theorem from Worldline Non-Injectivity: Exchange Phase, Rapidity, and Topological Sheet Structure For nearly a century, the Pauli exclusion principle (PEP) and the spin-statistics theorem have stood as foundational postulates of quantum mechanics and relativistic quantum field theory. The PEP dictates that no two identical fermions can occupy the same quantum state, determining the structure of atoms, the stability of matter, and the properties of neutron stars and white dwarfs. The spin-statistics theorem connects the intrinsic spin of a particle to its statistical behavior: half-integer spin particles (fermions) obey Fermi-Dirac statistics, while integer spin particles (bosons) obey Bose-Einstein statistics. Despite their universal success, these principles have never been derived from a more primitive geometric or topological principle — until now. This paper demonstrates that both the Pauli exclusion principle and the spin-statistics theorem emerge naturally and rigorously from a single geometric fact: the **non-injectivity of a timelike worldline** for Lorentz factors exceeding a critical threshold, \(\gamma > \gamma_{\text{crit}}\). In this regime, a single worldline intersects a constant-time hypersurface \(\Sigma_t\) in \(N > 1\) distinct spatial points, generating a multi‑sheet spacetime structure. This phenomenon, known as **worldline non-injectivity**, is the foundation of the TPST–DGQ framework. **Key results and logical flow:** 1. **Multi‑sheet structure for a single particle:** For \(\gamma > \gamma_{\text{crit}}\), a particle's worldline produces \(N(\epsilon) \sim \epsilon^{-(d-2)}\) topological sheets, each carrying the same physical properties (mass, charge, spin) via the Ontological Identity Principle. 2. **Composite worldline for two identical particles:** By combining two identical particles into a composite worldline in configuration space, we obtain a two‑particle sheet structure. Identical particles share isomorphic sheet structures, reducing the \(N \times N\) sheet pairs to \(N\) independent pairs. 3. **Exchange as a permutation of sheet blocks:** The exchange operator \(P_{12}\) swaps the sheet blocks associated with the two particles. This permutation is a topological operation in the two‑particle configuration space. 4. **Exchange phase from winding number:** The exchange path corresponds to half of a complete winding cycle around the fold structure of the composite worldline. The accumulated topological phase is \(\Phi_{\text{exchange}} = \pi w\), where \(w\) is the **winding number** of the worldline. Hence the exchange phase factor is \(\eta = e^{i\pi w} = (-1)^w\). 5. **Spin from winding number:** The winding number \(w\) is directly related to the spin \(s\) by the requirement that a \(4\pi\) rotation returns the physical state to itself (single‑valuedness). This yields \(w = 2s\). Therefore \(\eta = (-1)^{2s}\): half‑integer spin gives \(\eta = -1\) (fermions, antisymmetric), integer spin gives \(\eta = +1\) (bosons, symmetric). This is the spin‑statistics theorem derived from geometry. 6. **Pauli exclusion principle:** For two identical fermions (\(\eta = -1\)) at spatial coincidence, the two‑particle amplitude satisfies \(\mathcal{A} = \eta\mathcal{A}\), forcing \(\mathcal{A} = 0\). Thus no two fermions can occupy the same quantum state. The PEP is no longer a postulate; it is a theorem. 7. **Rapidity as inter‑sheet phase measure:** The rapidity \(\zeta = \operatorname{artanh}(v/c)\) is shown to be a monotonic function of the inter‑sheet phase difference \(\Phi_n\). The non‑injectivity threshold \(\gamma > \gamma_{\text{crit}}\) corresponds to \(\zeta > \zeta_{\text{crit}}\). The speed of light \(c\) emerges as the asymptotic limit where the inter‑sheet phase diverges, making \(v = c\) unreachable for massive particles. 8. **Universal cancellation identity:** The same algebraic identity \(N(\epsilon)\cdot\epsilon^{d-2} = O(1)\) that regularizes holographic entropy, Coulomb self‑energy, wavefunction normalization, electromagnetic fields, and the cosmological constant also regularizes the two‑particle exchange amplitude — zero for fermions, finite for bosons. Quantum statistics thus joins the list of phenomena unified under the principle of worldline non‑injectivity. **Implications:** This work completes the derivation of the foundations of quantum mechanics within the TPST–DGQ framework, following previous derivations of the Born rule, the Schrödinger equation, Planck’s constant, and wavefunction collapse. It also establishes a geometric origin for the spin‑statistics connection, a result that in standard physics relies on the heavy machinery of relativistic quantum field theory (unitarity, causality, positivity of energy). Here, it follows from the topology of worldline folds. This manuscript is current in Official Peer Review. Not final version.Copyright©2026 Alex De Giuseppe.All rights reserved. This work is protected by copyright. Any form of plagiarism, unauthorized reproduction, or misappropriation of ideas, mathematically results, or text without proper citation constitutes a violation of academic and intellectual property standards and common laws. No commercial use, adaptation, or derivative works are permitted without explicit written permission from the author. For correspondence, citations, collaboration inquiries, or feedback please contact:degiuseppealex@gmail.com The hash files that determine ownership have been created.

•Apr 1, 2026•0 citations
Bosons have symmetric wave function under particle exchange, while fermions have antisymmetric wave functions. This leads to differences in behavior of the two kinds of particles even in the gaseous state. Strong repulsive forces between atoms at close range are due to the Pauli principle that forbids two electrons to be in the same energy or position state. A repulsive Pauli pressure operates similarly in white dwarf stars. Bosons undergo Bose–Einstein condensation because of Bose statistics. The wave function symmetry of particles with spin can affect the magnetic states and the behavior of transport properties, for example, viscosity and thermal conductivity. The symmetry properties of bosons at a beam splitter are demonstrated in the Hong–Ou–Mandel effect or in a Michelson interferometer via the Hanbury Brown-Twiss effect. Researchers see boson bunching and fermion antibunching in experiments considered.
We discuss the bosonization of a relativistic very dense Fermi gas in a magnetic field and the consequent Bose–Einstein condensation of the resulting relativistic vector gas of charged particles. The model may be applied to paired spin-up electrons. We show that such systems may maintain self-consistently magnetic fields of order 10 10 −10 13 G. That pairing could be the origin of large magnetic fields in some white dwarfs and neutron stars. For fields large enough (~10 13 for white dwarfs), the system becomes unstable and collapses.
The Pauli Exclusion Principle and the Spin-Statistics Theorem from Worldline Non-Injectivity: Exchange Phase, Rapidity, and Topological Sheet Structure For nearly a century, the Pauli exclusion principle (PEP) and the spin-statistics theorem have stood as foundational postulates of quantum mechanics and relativistic quantum field theory. The PEP dictates that no two identical fermions can occupy the same quantum state, determining the structure of atoms, the stability of matter, and the properties of neutron stars and white dwarfs. The spin-statistics theorem connects the intrinsic spin of a particle to its statistical behavior: half-integer spin particles (fermions) obey Fermi-Dirac statistics, while integer spin particles (bosons) obey Bose-Einstein statistics. Despite their universal success, these principles have never been derived from a more primitive geometric or topological principle — until now. This paper demonstrates that both the Pauli exclusion principle and the spin-statistics theorem emerge naturally and rigorously from a single geometric fact: the **non-injectivity of a timelike worldline** for Lorentz factors exceeding a critical threshold, γ>γcrit\gamma > \gamma_{\text{crit}}γ>γcrit​. In this regime, a single worldline intersects a constant-time hypersurface Σt\Sigma_tΣt​ in N>1N > 1N>1 distinct spatial points, generating a multi‑sheet spacetime structure. This phenomenon, known as **worldline non-injectivity**, is the foundation of the TPST–DGQ framework. **Key results and logical flow:** 1. **Multi‑sheet structure for a single particle:** For γ>γcrit\gamma > \gamma_{\text{crit}}γ>γcrit​, a particle's worldline produces N(ϵ)∼ϵ−(d−2)N(\epsilon) \sim \epsilon^{-(d-2)}N(ϵ)∼ϵ−(d−2) topological sheets, each carrying the same physical properties (mass, charge, spin) via the Ontological Identity Principle. 2. **Composite worldline for two identical particles:** By combining two identical particles into a composite worldline in configuration space, we obtain a two‑particle sheet structure. Identical particles share isomorphic sheet structures, reducing the N×NN \times NN×N sheet pairs to NNN independent pairs. 3. **Exchange as a permutation of sheet blocks:** The exchange operator P12P_{12}P12​ swaps the sheet blocks associated with the two particles. This permutation is a topological operation in the two‑particle configuration space. 4. **Exchange phase from winding number:** The exchange path corresponds to half of a complete winding cycle around the fold structure of the composite worldline. The accumulated topological phase is Φexchange=πw\Phi_{\text{exchange}} = \pi wΦexchange​=πw, where www is the **winding number** of the worldline. Hence the exchange phase factor is η=eiπw=(−1)w\eta = e^{i\pi w} = (-1)^wη=eiπw=(−1)w. 5. **Spin from winding number:** The winding number www is directly related to the spin sss by the requirement that a 4π4\pi4π rotation returns the physical state to itself (single‑valuedness). This yields w=2sw = 2sw=2s. Therefore η=(−1)2s\eta = (-1)^{2s}η=(−1)2s: half‑integer spin gives η=−1\eta = -1η=−1 (fermions, antisymmetric), integer spin gives η=+1\eta = +1η=+1 (bosons, symmetric). This is the spin‑statistics theorem derived from geometry. 6. **Pauli exclusion principle:** For two identical fermions (η=−1\eta = -1η=−1) at spatial coincidence, the two‑particle amplitude satisfies A=ηA\mathcal{A} = \eta\mathcal{A}A=ηA, forcing A=0\mathcal{A} = 0A=0. Thus no two fermions can occupy the same quantum state. The PEP is no longer a postulate; it is a theorem. 7. **Rapidity as inter‑sheet phase measure:** The rapidity ζ=artanh⁡(v/c)\zeta = \operatorname{artanh}(v/c)ζ=artanh(v/c) is shown to be a monotonic function of the inter‑sheet phase difference Φn\Phi_nΦn​. The non‑injectivity threshold γ>γcrit\gamma > \gamma_{\text{crit}}γ>γcrit​ corresponds to ζ>ζcrit\zeta > \zeta_{\text{crit}}ζ>ζcrit​. The speed of light ccc emerges as the asymptotic limit where the inter‑sheet phase diverges, making v=cv = cv=c unreachable for massive particles. 8. **Universal cancellation identity:** The same algebraic identity N(ϵ)⋅ϵd−2=O(1)N(\epsilon)\cdot\epsilon^{d-2} = O(1)N(ϵ)⋅ϵd−2=O(1) that regularizes holographic entropy, Coulomb self‑energy, wavefunction normalization, electromagnetic fields, and the cosmological constant also regularizes the two‑particle exchange amplitude — zero for fermions, finite for bosons. Quantum statistics thus joins the list of phenomena unified under the principle of worldline non‑injectivity. **Implications:** This work completes the derivation of the foundations of quantum mechanics within the TPST–DGQ framework, following previous derivations of the Born rule, the Schrödinger equation, Planck’s constant, and wavefunction collapse. It also establishes a geometric origin for the spin‑statistics connection, a result that in standard physics relies on the heavy machinery of relativistic quantum field theory (unitarity, causality, positivity of energy). Here, it follows from the topology of worldline folds. This manuscript is current in Official Peer Review. Not final version.Copyright©2026 Alex De Giuseppe.All rights reserved. This work is protected by copyright. Any form of plagiarism, unauthorized reproduction, or misappropriation of ideas, mathematically results, or text without proper citation constitutes a violation of academic and intellectual property standards and common laws. No commercial use, adaptation, or derivative works are permitted without explicit written permission from the author. For correspondence, citations, collaboration inquiries, or feedback please contact:degiuseppealex@gmail.com The hash files that determine ownership have been created.