LINEAR POTENTIALS AND GALACTIC ROTATION CURVES

We present a simple, closed-form expression for the potential of an ax isymmetric disk of stars interacting through gravitational potentials of the form V(r) = -beta/r + gammar/2, the potential associated with f undamental sources in the conformal invariant fourth-order theory of g ravity which has recently been advanced by Mannheim and Kazanas as a c andidate alternative to the standard second-order Einstein theory. Usi ng the model, we obtain a reasonable fit to some representative galact ic rotation curve data without the need for any nonluminous or dark ma tter. Our study suggests that the observed flatness of rotation curves might only be an intermediate phenomenon rather than,an asymptotic on e.