Two-component millicharged dark matter and the EDGES 21cm signal

Abstract

We propose a two-component dark matter explanation to the EDGES 21 cm anomalous signal. The heavier dark matter component is long-lived whose decay is primarily responsible for the relic abundance of the lighter dark matter which is millicharged. To evade the constraints from CMB, underground dark matter direct detection, and XQC experiments, the lifetime of the heavier dark matter has to be larger than $0.1{\tau }_U$, where ${\tau }_U$ is the age of the universe. Our model provides a viable realization of the millicharged dark matter model to explain the EDGES 21 cm, since the minimal model in which the relic density is generated via thermal freeze-out is ruled out by various constraints.

13 pages, 2 figures

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Cited by in corpus (7)

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• Results on photon-mediated dark matter-nucleus interactions from the PICO-60 C${}_3$F${}_8$ bubble chamber
• XQC and CSR constraints on strongly interacting dark matter with spin and velocity dependent cross sections
• Exploring millicharged dark matter components from the shadows
• Freeze-in dark matter in EDGES 21-cm signal
• EDGES of the dark forest: A new absorption window into the composite dark matter and large scale structure
• Sensitivities on non-spinning and spinning primordial black hole dark matter with global 21 cm troughs