# Ultra-diffuse galaxies without dark matter

## TL;DR

This paper proposes a high velocity galaxy collision model to explain ultra-diffuse galaxies with little dark matter, predicting globular cluster formation, high relative velocities, and detectable dark halos with relic stars.

## Contribution

It introduces a novel collision-based model to account for dark matter-deficient ultra-diffuse galaxies, linking their properties to early universe dynamics.

## Key findings

- Overpressured dense clouds form globular clusters.
- High relative velocities in protogroup environments.
- Dark halos with relic low metallicity stars may be detectable.

## Abstract

I develop a high velocity galaxy collision model to explain a rare but puzzling phenomenon, namely the apparent existence of ultra-diffuse galaxies with little dark matter. Predictions include simultaneous triggering of overpressured dense clouds to form luminous old globular clusters, a protogroup environment to generate high relative velocities of the initially gas-rich galaxies in the early universe, and spatially separated dark halos, possibly detectable via gravitational lensing and containing relic low metallicity stars with enhanced [alpha/Fe] at ultralow surface brightness.