Dark Matter at Cosmic Dawn

Dark Matter at Cosmic DawnLow-frequency radio observations could allow researchers to distinguish among several dark matter models, thanks to dark matter's influence on the early Universe. By Charles DayT he profusion of dark matter candidates reflects how easy it is for any of them to explain the current large-scale structure of the Universe.Decisive clues about dark matter's true nature are more likely to appear at earlier epochs.Unfortunately, those clues are harder to observe.Now Jo Verwohlt of the University of Copenhagen in Denmark and her collaborators have shown how a deeply redshifted hydrogen line could unmask dark matter [1].To do so, they also identified confounding signatures from regular, baryonic matter.