The Redshift-Dependence of Radial Acceleration: Modified Gravity versus
  Particle Dark Matter
  Modified Newtonian Dynamics has one free parameter and requires an
interpolation function to recover the normal Newtonian limit. We here show that
this interpolation function is unnecessary in a recently proposed covariant
completion of Erik Verlinde's emergent gravity, and that Verlinde's approach
moreover fixes the function's one free parameter. The so-derived correlation
between the observed acceleration (inferred from rotation curves) and the
gravitational acceleration due to merely the baryonic matter fits well with
data. We then argue that the redshift-dependence of galactic rotation curves
could offer a way to tell apart different versions of modified gravity from
particle dark matter.
