Probing the effects of primordial black holes on 21-cm EDGES signal along with interacting dark energy and dark matter–baryon scattering

Abstract

ABSTRACT21-cm radio signal has emerged as an important probe in investigating the dark age of the Universe (recombination to reionization). In the current analysis, we explore the combined effects of primordial black holes (PBHs), cooling-off of the baryonic matter due to dark matter (DM)–baryon collisions and interaction of DM and dark energy fluid on the 21-cm brightness temperature. The variation of brightness temperature shows remarkable dependence on DM mass (mχ) and the DM–baryon scattering cross-section (σ0). Bounds in mχ–σ0 parameter space are obtained for different possible PBH masses and for different interacting dark energy (IDE) models. These bounds are estimated based on the observed excess ($-500^{+200}_{-500}$ mK) of 21-cm brightness temperature by Experiment to Detect the Global Epoch of Reionization Signature experiment. Eventually, bounds on PBH mass is also obtained for different values of DM mass and for different IDE model coupling parameters. The compatibility of the constraints of the IDE models, in the estimated bounds is also addressed.