# Bounds on Dark Matter annihilations from 21 cm data

## TL;DR

This paper derives bounds on dark matter annihilation cross sections using 21 cm spectrum data, showing that such bounds are comparable to the strongest existing constraints across various dark matter masses.

## Contribution

It provides new bounds on dark matter annihilation cross sections based on 21 cm observations, extending the range of constraints from astrophysical data.

## Key findings

- Bounds on DM annihilation cross sections are comparable to the strongest existing limits.
- The 21 cm absorption feature constrains significant heating from DM annihilations.
- Results apply across a broad range of dark matter masses.

## Abstract

The observation of an absorption feature in the 21 cm spectrum at redshift $z\approx 17$ implies bounds on Dark Matter annihilations for a broad range of masses, given that significant heating of the intergalactic medium would have erased such feature. The resulting bounds on the DM annihilation cross sections are comparable to the strongest ones from all other observables.