Probing Interacting Dark Energy and Scattering of Baryons with Dark Matter in Light of EDGES 21cm Signal

Understand

The EDGES experiment has observed an excess trough ($-500^{+200}_{-500}$ mK) in the brightness temperature $T_{21}$ of the 21cm absorption line of neutral Hydrogen atom (HI) from the era of cosmic dawn ($z \simeq 17.2$).

• We consider possible interaction of Dark Matter and Dark Energy fluid along with the cooling off of the baryon matter by its collision with Dark Matter to explain the observed excess trough of $T_{21}$.
• We make use of three different Dark Matter-Dark Energy (DM-DE) interaction models to taste the viability of those models in explaining the EDGES results.
• The evolution of Hubble parameter is modified by DM-DE interactions and this is also addressed in this work.