# Primordial dark matter halos from fifth forces

## TL;DR

This paper proposes that long-range forces stronger than gravity could lead to the formation of primordial dark matter halos during radiation domination, affecting dark matter distribution and detection strategies.

## Contribution

It derives conditions for primordial halos formed by fifth forces to dominate dark matter, consistent with observational constraints.

## Key findings

- Primordial halos could be solar mass objects with solar system sizes.
- Such structures could influence direct dark matter detection.
- Conditions for formation are compatible with microlensing and CMB bounds.

## Abstract

We argue that primordial dark matter halos could be generated during radiation domination by long range attractive forces stronger than gravity. In this paper we derive the conditions under which these structures could dominate the dark matter content of the Universe while passing microlensing constraints and cosmic microwave background energy injection bounds. The dark matter particles would be clumped in objects in the solar mass range with typical sizes of the order of the solar system. Consequences for direct dark matter searches are important.