{\Lambda} CDM is Consistent with SPARC Radial Acceleration Relation

TL;DR

This study demonstrates that the tight radial acceleration relation observed in galaxies can be explained within the standard DM cosmology through baryonic physics, without requiring new physics or modifications to gravity.

Contribution

The paper shows that DM cosmological simulations can reproduce the observed acceleration relation with less scatter, challenging claims that it indicates new physics.

Findings

32 simulated galaxies match the SPARC acceleration relation

Simulations with DM cosmology reproduce the relation with less scatter

The relation arises from baryonic dissipative collapse, not new physics

Abstract

Recent analysis \citep{McGaugh2016} of the SPARC galaxy sample found a surprisingly tight relation between the radial acceleration inferred from the rotation curves, and the acceleration due to the baryonic components of the disc. It has been suggested that this relation may be evidence for new physics, beyond $\Lambda CDM$. In this letter we show that 32 galaxies from the MUGS2 match the SPARC acceleration relation. These cosmological simulations of star forming, rotationally supported discs were simulated with a {\sc WMAP3} $\Lambda CDM$ cosmology, and match the SPARC acceleration relation with less scatter than the observational data. These results show that this acceleration relation is a consequence of dissipative collapse of baryons, rather than being evidence for exotic dark-sector physics or new dynamical laws.