MOND and the mass discrepancies in tidal dwarf galaxies

TL;DR

This paper demonstrates that MOND accurately predicts the rotation curves of three tidal dwarf galaxies without requiring dark matter, challenging the cold dark matter paradigm.

Contribution

It shows that MOND can explain the observed velocities of tidal dwarf galaxies solely with visible baryonic matter, countering claims for additional dark matter in these systems.

Findings

MOND predictions align with observed velocities

No need for additional dark matter in tidal dwarf galaxies

Challenges the cold dark matter paradigm in these cases

Abstract

I consider in light of MOND the three debris galaxies discussed recently by Bournaud et al.. These exhibit mass discrepancies of a factor of a few within several scale lengths of the visible galaxy, which, arguably, flies in the face of the cold dark matter paradigm. I show here that the rotational velocities predicted by MOND agree well with the observed velocities for each of the three galaxies, with only the observed baryonic matter as the source of gravity. There is thus no need to invoke a new form of baryonic, yet-undetected matter that dominates the disc of spiral galaxies, as advocated by Bournaud et al. I argue on other grounds that the presence of such ubiquitous disc dark matter, in addition to cold dark matter, is not likely.