Impact of a global quadratic potential on galactic rotation curves

Understand

We have made a conformal gravity fit to an available sample of 110 spiral galaxies, and report here on the 20 of those galaxies whose rotation curve data points extend the furthest from galactic centers.

• We identify the impact on the 20 galaxy data set of a universal de Sitter-like potential term $V(r)=-\kappa c^2r^2/2$ that is induced by inhomogeneities in the cosmic background.
• This quadratic term accompanies a universal linear potential term $V(r)=\gamma_0c^2r/2$ that is associated with the cosmic background itself.
• We find that when these two potential terms are taken in conjunction with the contribution generated by the local luminous matter within the galaxies, the conformal theory is able to account for the rotation curve systematics that is observed in the entire 110 galaxy sample, without the need for any dark matter whatsoever.