Interacting dark energy: possible explanation for 21-cm absorption at cosmic dawn André A. Costa, Ricardo C. G. Landim, Bin Wang and Elcio Abdalla Eur. Phys. J. C, 78 9 (2018) 746 Published online: 18 September 2018 DOI: 10.1140/epjc/s10052-018-6237-7