Galactic Rotation Curves and Linear Potential Laws
  We study the possibility that galactic rotation curves can be explained by a gravitational potential that contains a linear term as well as a Newtonian one. This hypothesis, suggested by conformal gravity, does allow good fits to the galactic rotation curves of the galaxies we study, which have a wide range of luminosities. However, the universality one might have expected of the parameter describing the strength of the linear potential does not emerge. Instead, a different regularity is seen. 
Carl E. Carlson and Eric J. Lowenstein