The Hydrodynamics of Dark Matter: Viscous Entrainment and Virtual Mass in a Kelvin-Voigt Vacuum

Abstract: The “Missing Mass” problem remains the most significant failure of General Relativity. The standard ΛCDM model postulates a halo of invisible, non-baryonic matter to explain galactic rotation curves and virial discrepancies. However, this model struggles to explain the morpho-logical diversity of Dark Matter ratios, particularly in Dwarf Spheroidals (high DM fraction) and Ultra-Diffuse Galaxies (low/zero DM fraction). This paper proposes a solution within the framework of the Deus Cosmological Model (DCM), treating the vacuum as a Viscoelastic Kelvin-Voigt Solid. We demonstrate that “Dark Matter” is not a substance, but a hydrodynamic effect: the Viscous Entrainment of the spacetime lattice by massive, rotating bodies. We derive the Rotation Curve v(r) as a sum of Newtonian gravity and a Viscous Wake term, successfully reproducing flat rotation curves. Furthermore, we demonstrate that this hydrodynamic model naturally predicts the anomalous Dark Matter fractions observed in Ellipticals, DwarfSpheroidals, and UDGs based on Reynolds Number scaling and vorticity, without requiring fine-tuned halo parameters.