Constraining spinning primordial black holes with global 21-cm signal

Understand

We study the upper projected bounds on the dark matter fraction in the form of the primordial black holes (PBHs) with a non-zero spin by using the absorption feature in the global 21-cm signal at redshift z ~ 17.

• The mass and spin are fundamental properties of a black hole, and they can substantially affect the evaporation rate of the black hole.
• The evaporating black hole can inject energy into the intergalactic medium and heat the gas.
• Subsequently, it can modify the absorption amplitude in the global 21-cm signal.