Acceleration in Modified Gravity (MOG) and the Mass-Discrepancy Baryonic Relation

TL;DR

This paper explores a modified gravity theory (MOG) that adjusts Newtonian gravity with two parameters, successfully explaining galaxy rotation curves and cluster dynamics without dark matter.

Contribution

It demonstrates that MOG's acceleration law aligns with observed galaxy rotation curves and the baryonic mass-acceleration relation across diverse astronomical systems.

Findings

MOG fits galaxy rotation curves without dark matter.

MOG explains galaxy cluster dynamics.

Agreement with the McGaugh et al. baryonic relation.

Abstract

The equation of motion in the generally covariant modified gravity (MOG) theory leads for weak gravitational fields and the non-relativistic limit to a modification of the Newtonian gravitational acceleration law, expressed in terms of two parameters $\alpha$ and $\mu$. The parameter $\alpha$ determines the strength of the gravitational field and $\mu$ is the effective mass of the vector field $\phi_\mu$, coupled with gravitational strength to baryonic matter. The MOG acceleration law for weak field gravitation and non-relativistic particles has been demonstrated to fit a wide range of galaxies, galaxy clusters and the Bullet Cluster and Train Wreck Cluster mergers. We demonstrate that the MOG acceleration law for a point mass source is in agreement with the McGaugh et al., correlation between the radial acceleration traced by galaxy rotation curves and the distribution of baryonic matter for the SPARC sample of 153 rotationally supported spiral and irregular galaxies.