Probing Interacting Dark Energy and Scattering of Baryons with Dark
  Matter in Light of EDGES 21cm Signal
  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. This in
turn influences the optical depth of HI 21cm as well as the baryon temperature
and thus effects the $T_{21}$ brightness temperature. In addition we also find
that the DM-DE interaction enables us to explore Dark Matter with varied mass
regimes and their viabilities in terms of satisfying the EDGES result.
