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

TL;DR

This study investigates how primordial black holes, dark matter-baryon interactions, and dark energy-dark matter interactions collectively influence the 21-cm signal, providing new bounds on PBH and dark sector parameters based on EDGES observations.

Contribution

It presents the first combined analysis of PBH effects, dark matter-baryon scattering, and dark energy-dark matter interaction on the 21-cm brightness temperature, deriving new constraints from EDGES data.

Findings

Bounds on dark matter mass and scattering cross-section are established.

Constraints on PBH mass are derived for various dark matter and dark energy models.

Compatibility of dark energy interaction models with observational bounds is analyzed.

Abstract

21-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 (PBH), cooling off of the baryonic matter due to dark matter (DM) - baryon collisions and interaction of dark matter - dark energy (DE) fluid on the 21-cm brightness temperature. The variation of brightness temperature shows remarkable dependence on DM mass ($m_{\chi}$) and the dark matter - baryon scattering cross-section ($\sigma_0$). Bounds in $m_{\chi}$ - $\sigma_0$ 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 EDGES experiment. Eventually, bounds on PBH mass is also obtained for different values of dark matter mass and for different IDE model coupling parameters. The compatibility of the constraints of the IDE models, in the estimated bounds are also addressed.