THE CHRONO-GEOMETRY OF THE β-VACUUM: PHYSICAL ORIGIN, PROOFS, AND CONSEQUENCES OF A FOURTH-ORDER FLUID : Unification of beta-MHD, Cosmology, and Propulsion without Mass Ejection

We introduce the β-Vacuum as the dominant fourth-order low-energy contribution of the vacuum within an effective field theory framework. It is described by a classical scalar field Φ with energy density F_β = (β/4)(∂_μ Φ ∂^μ Φ)². The single parameter β has the dimension of action per velocity [J ⋅ m] = [kg ⋅ m³ ⋅ s⁻²]. We demonstrate that what has historically been called "dark energy" and "dark matter" are not independent substances but two distinct observable effects arising from the temporal and spatial components of a single β-Vacuum field. We prove: 1. global existence of solutions of the beta-MHD system Th 3.2 via monotonicity and hyper-viscosity, 2. the complete derivation of the energy-momentum tensor T^β_μν Eq 5.3f, 3. the emergence of a cosmological effect Λ_β ∝ a⁻⁴ Th 5.6, 4. the emergence of a galactic structuring effect Th 5.7 with explicit asymptotic solution Lemma 5.7a, 5. the propulsion law F = β A Q Γ⁴ Th 4.1, 6. laboratory detectability Th 7.1, 7. the creation of cosmological horizons Th 9.1, 8. effective superluminal transport via metric engineering Th 9.2, 9. causal self-censorship Th 3.3, 10. consistency with local constraints Th 6.2. The value of β is fixed by joint fitting: β = 1.27 × 10⁻¹ J ⋅ m Th 6.1. The model predicts 5 measurable deviations: Hartmann profile flattening of 0.28% Eq 7.9, CMB running dn_s/dln k = -1.1×10⁻⁴ Eq 7.10, 4.8% suppression of fσ₈ at z=2 Eq 7.12, finite cores Cor 5.8, reduced decoupling Th 5.9. For Γ → 0 one recovers exactly Einstein + MHD + ΛCDM.