Curvature, Galactic Dynamics and Cosmic Repulsion
  We show that a cosmological negative spatial curvature can account for both a recently identified phenomenological imprint of the global Hubble flow on galactic rotation curves and for the recently detected cosmic repulsion and cosmic acceleration. Even though such a negative curvature (a curvature which a galactic rest frame observer recognizes as a universal linear potential which gives rise to a universal acceleration) is only achievable in standard gravity by extreme fine tuning, nonetheless, it is naturally realizable in conformal gravity, a currently viable, fully covariant, candidate alternate gravitational theory. 
Philip D. Mannheim (University of Connecticut)