Cores in Dwarf Galaxies from Dark Matter with a Yukawa Potential

TL;DR

This paper proposes that dark matter particles interacting via a Yukawa potential can naturally produce core-like structures in dwarf galaxies while remaining consistent with larger-scale observations, offering a new explanation for small-scale galactic features.

Contribution

It introduces a Yukawa potential-based dark matter model that explains dwarf galaxy cores without conflicting with galaxy cluster dynamics.

Findings

Yukawa interactions produce velocity-dependent cross-sections.

Dark matter evaporation may explain satellite galaxy deficits.

Implications for early galaxy formation and reionization.

Abstract

We show that cold dark matter particles interacting through a Yukawa potential could naturally explain the recently observed cores in dwarf galaxies without affecting the dynamics of objects with a much larger velocity dispersion, such as clusters of galaxies. The velocity dependence of the associated cross-section as well as the possible exothermic nature of the interaction alleviates earlier concerns about strongly interacting dark matter. Dark matter evaporation in low-mass objects might explain the observed deficit of satellite galaxies in the Milky Way halo and have important implications for the first galaxies and reionization.