Lava-Void Cosmology Pillar 11: UHECR Propagation & The Oh-My-God (OMG) Particle

The Navigable Universe: Entropy as the Substrate of Physical Structure, Time's Arrow, and the Cosmic Sailor: https://zenodo.org/records/18755741 Lava-Void Cosmology Master Briefing Document:https://www.mylivingai.com/wp-content/uploads/2026/02/LVC_Master_Briefing.pdf This document establishes the eleventh pillar of Lava-Void Cosmology (LVC): Ultra-High-Energy Cosmic Ray (UHECR) Physics. The 1991 "Oh-My-God" particle (300 EeV) remains a fundamental tension in ΛCDM, apparently violating the GZK cutoff. Pillar 11 provides a mathematically rigorous reinterpretation of this event as a Guided Fluid Excitation propagating through low-density void channels. Key Technical Breakthroughs: The $f_{LVC}$ Phenomenological Extension: A new parametric multiplier for standard transport treatments. We demonstrate that LVC void-channeling effectively rescales the integrated optical depth, extending cosmic horizons by factor 10–20. CRPropa 3.2 Calibration: Numerical results are anchored to public CRPropa benchmarks, ensuring consistency with established microphysical cross-sections. The Void-Aligned Dipole Test ($d_{void}$): Introduction of a pipeline-ready anisotropy statistic to cluster arrival directions along reconstructed void axes (ZOBOV/DESI). Mock Data Recovery: Proof of concept demonstrating $>5\sigma$ detectability for the predicted LVC signal in upcoming datasets (AugerPrime, POEMMA). This record completes the Lava-Void Endecad, providing the direct code parameters and likelihood functions required for imminent experimental falsification. PILLAR 11: THE OMG PARTICLE & VOID CHANNELS Mechanism: Guided excitation along low-density void channels. f_LVC Parameter: A multiplicative boost (5–20x) to the effective attenuation length $\lambda(E)$. GZK Resolution: Distant sources ($>500$ Mpc) become viable for trans-GZK events without new physics. The Falsifier: The Void-Aligned Dipole ($d_{void}$). Predicts arrival directions cluster along reconstructed void axes (ZOBOV/DESI). Update 11.1: Updated UHECR Constraints, Composition Predictions, and Multi-Messenger Integration in the Lava-Void UHECR Framework Pillar 11 now reflects the latest observational landscape while preserving computational readiness and statistical discrimination power. With these extensions, Pillar 11 achieves exhaustive completeness as the ultra-high-energy cosmic-ray implementation pillar of Lava-Void Cosmology. https://www.mylivingai.com/wp-content/uploads/2026/02/Pillar-11-Ext-1.pdf Pillar 11 Extension: Closing the UHECR Loopholes — Void Channeling, the OMG Particle, and the GZK Horizon February 2026 Subsection 11.2: Rigorous Defense of Viscous Void Channeling for Ultra-High-Energy Cosmic RaysOfficial DOI (P11): 10.5281/zenodo.18116535 11.2.1 Motivation Pillar 11 claims that ultra-high-energy cosmic rays (UHECRs), including the 300 EeV "Oh-My-God" (OMG) particle detected by the Fly's Eye experiment in 1991, are explained by viscous void channeling — UHECRs propagating through cosmic voids experience reduced energy loss because the void phase has lower photon density and lower viscous interaction cross-section. This extends the UHECR attenuation length by a factor of 5–20×, resolving the apparent violation of the GZK cutoff. The attack surface: The GZK cutoff: Is void channeling sufficient to explain trans-GZK events quantitatively? Source identification: Can void-channeled UHECRs be traced to specific sources? The dipole anisotropy: Does the void-channeling model predict the observed large-scale UHECR anisotropy? Composition: Auger data suggest heavy composition at the highest energies. Is this consistent with void channeling? Discrimination: How does void channeling differ from standard astrophysical explanations? 11.2.2 The GZK Cutoff and Its Apparent Violation 11.2.2.1 Standard GZK Physics The Greisen-Zatsepin-Kuzmin (GZK) cutoff predicts that cosmic ray protons with energy E > 6 × 1019 eV (~60 EeV) should lose energy rapidly via photopion production on CMB photons: p + γCMB → Δ+ → p + π0 (or n + π+) The energy loss length for this process is: λGZK = 1 / (nγ · σpγ · κ) ≈ 50 Mpc where nγ ≈ 410 cm−3 is the CMB photon density, σpγ ≈ 0.5 mb is the photopion cross-section at the Δ resonance, and κ ≈ 0.2 is the inelasticity. Sources beyond ~100 Mpc should not contribute to the observed flux above 60 EeV. The OMG particle (E ≈ 320 EeV) has no identified source within 100 Mpc in the arrival direction. Either it came from nearby (no plausible source) or it traveled much farther than the GZK limit allows. 11.2.2.2 The LVC Resolution: Reduced CMB Density in Voids In LVC, cosmic voids are not empty space with uniform CMB — they are regions where the effective photon interaction rate is reduced. The mechanism is two-fold: 1. Geometric dilution: Voids expand faster than the cosmic mean (Hvoid > Hmean). Photons traversing a void are redshifted by the additional local expansion, reducing their energy in the UHECR rest frame. The effective CMB temperature experienced by a UHECR in a void is: Teff = TCMB · (1 − δ/3) ≈ TCMB · 0.87 for δ = −0.4 The photopion cross-section is steeply peaked at the Δ resonance (Eγ ≈ 145 MeV in the proton rest frame). The threshold UHECR energy for GZK interaction scales as EGZK ∝ 1/Teff. In a void: EGZK,void = EGZK,mean / (1 − δ/3) ≈ 60 / 0.87 ≈ 69 EeV This alone raises the effective cutoff by ~15% — helpful but insufficient for the OMG particle. 2. Photon density reduction: The CMB photon number density in a void is nγ,void = nγ,mean · (1 + δ)³ for a void with density contrast δ. For δ = −0.4: nγ,void = 410 · (0.6)³ ≈ 89 cm−3 Wait — this is incorrect. The CMB photon density is determined by the CMB temperature, not the matter density. Photons free-stream and are not trapped in voids. The CMB is isotropic to 10−5; there is no significant photon density variation between voids and filaments. 11.2.2.3 Corrected Mechanism: Viscous Shielding The geometric dilution effect (§11.2.2.2, mechanism 1) is real but small. The CMB photon density effect is negligible (the CMB is uniform). The primary LVC mechanism must therefore be different from simple photon density reduction. The corrected mechanism is viscous modification of the photopion cross-section: In the viscous fluid, the effective vacuum between a UHECR proton and CMB photons is not the standard QED vacuum — it is the LVC void-phase fluid with a finite (though very low) viscosity. The viscous medium modifies the photopion interaction in two ways: a) Effective mass modification: The proton, as a viscous vortex (Pillar 2), has an effective mass that depends on the local fluid density: meff(ρ) = mp · [1 + η(ρ)/(mpc · lvortex)] In void regions (low ρ), η is low, and meff ≈ mp (no significant change). In filaments (high ρ), meff > mp. This shifts the GZK threshold energy in filaments but not in voids — making filament traversal more lossy and void traversal unchanged. The net effect is that UHECRs preferentially survive in void-dominated paths. b) Path selection: The more important effect is geometric: UHECRs that happen to propagate along void channels — extended underdensities connecting source and observer — experience fewer interactions with intervening matter (galaxy clusters, filaments) that could scatter or degrade the particle. The void channel acts as a low-loss waveguide. The attenuation length enhancement factor is: fLVC = λeff / λGZK = [fpath,void + (1 − fpath,void) · (λGZK/λfilament)]−1 where fpath,void is the fraction of the propagation path in void regions and λfilament < λGZK is the (shorter) attenuation length in filaments due to enhanced photon and matter interactions. For a path that is 80% void (fpath,void = 0.8, consistent with the void fraction fv ≈ 0.7 and preferential void alignment): fLVC ≈ 1 / [0.8 · 1 + 0.2 · (50/30)] ≈ 1 / [0.8 + 0.33] ≈ 0.88 This gives only ~12% enhancement — insufficient. The factor of 5–20× claimed in Pillar 11 requires a stronger mechanism. 11.2.2.4 Honest Reassessment The original Pillar 11 claim of fLVC = 5–20× enhancement to the attenuation length is difficult to sustain with the corrected analysis. The primary mechanisms are: Geometric dilution (void temperature reduction): ~15% increase in EGZK Path selection (void-dominated trajectories): ~10–30% increase in effective λ Viscous cross-section modification: negligible at void densities The combined effect is a factor of ~1.3–1.5× in effective attenuation length — meaningful but far short of 5–20×. The fLVC = 5–20× claim requires revision. Two possibilities: The claim is too strong: LVC provides a modest (~30–50%) enhancement to UHECR propagation in voids, which helps explain the shape of the UHECR spectrum near the cutoff but does not fully resolve the OMG particle. The OMG particle may require a nearby source (within ~100 Mpc) that has not yet been identified, consistent with both LVC and ΛCDM. Additional mechanisms exist: The void-phase fluid may have properties beyond the simple GCG description that further reduce photopion interactions — e.g., if the void phase modifies the QED vacuum polarization at ultra-high energies (a speculative extension of §2.2.5.3). This would require new physics beyond the current LVC formulation and should be flagged as speculative. Revised claim: LVC provides a 30–50% enhancement to UHECR attenuation lengths in void-dominated paths, improving the fit to the observed trans-GZK flux by reducing the tension with distant sources. The OMG particle specifically remains an open problem in both LVC and ΛCDM. 11.2.3 The Void-Aligned Dipole 11.2.3.1 The Observed Anisotropy The Pierre Auger Observatory has measured a large-scale dipole anisotropy in the UHECR arrival directions above 8 EeV, with amplitude d = 6.5% and direction (ℓ, b) ≈ (233°, −13°) in Galactic coordinates. This direction is ~125° from the Galactic center and roughly aligned with the directi