Explaining the Results of EDGES Observation of 21 cm Line with Dark Matter-Dark Energy and Dark Matter-Baryon Interactions

The EDGES experiment related to the observation of the brightness temperature T 21 of the 21 cm line arising from the ground state of the neutral Hydrogen atom, has shown an excess absorption feature (-500 +200 -500 mK) in the T 21 spectrum corresponding to the era of the cosmic dawn (z ≃ 17.2).In order to explain the observed excess trough of T 21 , we consider an Interacting Dark Energy scenario (interactions of Dark Matter and Dark Energy) along with the scattering of baryons with Dark Matter.Three different Interacting Dark Energy (IDE) models are used, and the viability of these models is tested in the context of the EDGES experimental results.It is found that Dark Matter-Dark Energy interactions modify the evolution process of the Universe and, hence, affect the brightness temperature.Dark Matter-baryon interactions also affect the T 21 temperature since the baryon fluid would transfer heat to the colder Dark Matter fluid due to the Dark Matter-baryon collisions.In addition, we also give bounds on the model parameters of IDE models and Dark Matter model from the EDGES observational data.It is noted that Dark Matter-Dark Energy interactions enable exploring a larger range of Dark Matter mass regimes that would satisfy the EDGES result.