Resonant Dark Forces and Small Scale Structure

TL;DR

This paper explores how a dark force can influence dark matter's role in cosmic structure, explaining dwarf galaxy cores and relic density, with quantum resonances affecting self-scattering at GeV-TeV scales.

Contribution

It introduces a simple dark force model that simultaneously accounts for astrophysical bounds and relic density using a single coupling.

Findings

Dark matter self-scattering exhibits quantum resonances.

The model explains dwarf galaxy cores and relic density.

A single coupling constant suffices for all constraints.

Abstract

A dark force can impact the cosmological history of dark matter (DM), both explaining observed cores in dwarf galaxies and setting the DM relic density through annihilation to dark force bosons. For GeV - TeV DM mass, DM self-scattering in dwarf galaxy halos exhibits quantum mechanical resonances, analogous to a Sommerfeld enhancement for annihilation. We show that a simple model of DM with a dark force can accommodate all astrophysical bounds on self-interactions in halos and explain the observed relic density, through a single coupling constant.