Enlightening the dark ages with dark matter

TL;DR

This paper explores how future 21 cm radio surveys, especially lunar-based arrays, can provide new constraints on dark matter properties through detection of signals from the dark ages, surpassing current methods.

Contribution

It demonstrates the potential of 21 cm intensity mapping surveys, particularly lunar arrays, to detect dark matter signals with sensitivities beyond existing constraints.

Findings

Lunar far-side radio arrays could detect extremely weak dark matter signals.

Forthcoming radio surveys like SKA may detect some dark matter scenarios.

21 cm signals offer a complementary probe to existing dark matter detection methods.

Abstract

Constraints on dark matter annihilation or decay offer unique insights into the nature of dark matter. We illustrate how surveys dedicated to detect the highly redshifted 21 cm signal from the dark ages will offer a new window into properties of particle dark matter. The 21 cm intensity mapping signal and its fluctuations are sensitive to energy injection from annihilation or decay of long-lived particles in a way that is complementary to other probes. We present forecasted constraints from forthcoming and next-generation radio surveys. We show that, while SKA might be capable of a detection for some cases, the most promising opportunity to detect dark matter in the 21 cm intensity mapping signal is with a futuristic radio array on the lunar far-side, with the potential to detect a signal many orders of magnitude weaker than current or maximal constraints from other probes.