MOND Phenomenology from the Dark Matter Condensate
Description
Modified Newtonian Dynamics (MOND; Milgrom 1983) successfully describes galaxy rotation curves, the radial acceleration relation (RAR), and the baryonic Tully-Fisher relation with a single acceleration scale a₀ ≈ 1.2 × 10⁻¹⁰ m/s², yet fails for galaxy clusters, the Bullet cluster, and cosmological observables. We demonstrate that all of MOND's galactic successes emerge naturally from the Hopf soliton programme's dark matter condensate without modifying gravity. The dark matter — the knotting sector of the Faddeev-Niemi topological vacuum (Paper LXVII) — produces Burkert-like cored density profiles whose ρ ∝ r⁻³ outer envelopes yield flat rotation curves, the RAR at 0.141 dex scatter (Paper XCIII; observed 0.130 dex), and the baryonic Tully-Fisher relation M_b ∝ v_f⁴. The MOND acceleration scale is not fundamental: it equals 2π G Σ₀ where Σ₀ ≈ 140 M_⊙ pc⁻² is the Donato surface density, which traces back to ρ_Λ = 8α¹⁶ c_geom⁴ m_e⁴ (Paper XI) through structure formation. MOND's failures are resolved because the dark matter is real and collisionless (σ/m = 0). The framework predicts that the MOND external field effect should be absent — a decisive, falsifiable test distinguishing real dark matter from modified gravity.