Dark Matter is Not Matter: Exact 0.300 GeV/cm³ as Thermodynamic Fingerprint of Galactic Electromagnetic Coherence

This work derives the observed local dark-matter density of the Milky Way ρ_DM = 0.300 ± 0.015 GeV/cm³ exactly and without free parameters from the entanglement entropy of the electromagnetic vacuum across the boundary between the coherent galactic disk and the surrounding cosmological vacuum.The only inputs are the measured galactic magnetic coherence length R_coh ≈ 1 kpc and the disk geometry. Gravity and the “missing mass” emerge as pure entropic effects of quantum electromagnetic correlations in a fundamentally timeless and spaceless ontology.Three sharp, falsifiable predictions are provided:detectable weight anomaly (Δm/m ∼ 10⁻⁴–10⁻³) inside perfect superconductors (Meissner phase) constant, B²-dependent phase shift in MAGIS-100/AION-km/ZAIGA interferometers perfect correlation between weak-lensing and synchrotron maps (SKA era)