Galactic rotation curves in conformal gravity

TL;DR

This paper reviews how conformal gravity can explain galactic rotation curves without dark matter by incorporating local and global linear and quadratic potentials, fitting a large galaxy sample with minimal free parameters.

Contribution

It demonstrates that conformal gravity accurately models galactic rotation curves across diverse galaxies using only one free parameter per galaxy, challenging dark matter hypotheses.

Findings

Conformal gravity fits 141 galaxy rotation curves without dark matter.

The theory introduces local linear and global quadratic potentials.

A single free parameter per galaxy suffices for accurate modeling.

Abstract

We review some recent work by Mannheim and O'Brien on the systematics of galactic rotation curves in the conformal gravity theory. In this work the conformal theory was applied to a comprehensive, high quality sample of spiral galaxies whose rotation curves extend well beyond the galactic optical disks. On galactic scales the conformal gravitational theory departs from the standard Newtonian theory in two distinct ways. One is a local way in which local matter sources within galaxies generate not just Newtonian potentials but linear potentials as well. The other is a global way in which two universal global potentials, one linear the other quadratic, are generated by the rest of the matter in the universe. The study involves a broad set of 138 spiral galaxies of differing luminosities and sizes, and is augmented here through the inclusion of an additional three tidal dwarf galaxies. With its linear and quadratic potentials the conformal theory can account for the systematics of an entire 141 galaxy sample without any need for galactic dark matter, doing so with only one free parameter per galaxy, namely the visible galactic mass to light ratio.