Constraints on primordial black holes and curvature perturbations from the global 21-cm signal

Abstract

We investigate the effect of accreting primordial black holes (PBHs) on the thermal history of the intergalactic medium (IGM), including the accretion of baryonic matter and dark matter particle. The variations of the thermal history of the IGM caused by accreting PBHs will result in the changes of the global 21-cm signal in the cosmic dawn. Based on the detection of the global 21-cm signal by EDGES, by requiring the differential brightness temperature, e.g., δT21 < ∼ −100 (−50) mK, we obtain the upper limits on the abundance of PBHs for the mass range 10 < ∼ MPBH < ∼ 10 4 M . Compared with previous works, the limits are stronger for the mass range 10 < ∼ MPBH < ∼ 50 M .

Influences of accreting primordial black holes on the global 21 cm signal in the dark ages

“…In order to solve the differential equations mentioned above, we have followed the method used by e.g. Yang (2019Yang ( , 2015Yang ( , 2020 ) M⊙ and fPBH = 10 −1 (10 −3 ), respectively. For comparison, the standard case without accreting PBHs is also shown in Fig.…”

“…PBHs with masses MPBH ∼ 10 13 − 10 14 g, whose lifetime is smaller than the present age of the Universe, have evaporated in the redshift range z ∼ 6 − 1100. The observational results of EDGES can also be used to put upper limits on the initial mass fraction of these short-lived PBHs (Yang 2020;Halder & Banerjee 2021).…”

Exploring multimessenger signals from heavy dark matter decay with EDGES 21-cm result and IceCube

“…After incorporating the effects of energy injection from PBH evaporation and the baryon-DM interaction, the evolution equations (T χ and T b of Ref. [15]) take the form [2,3,15,36,37],…”

“…The 21-cm neutral hydrogen spectrum can be a promising probe in understanding the dynamics of the early Universe particularly during this unexplored era. The redshifted signature of the 21-cm hydrogen absorption spectrum may provide a detailed understanding regarding the reionization and the Primordial Black Holes (PBHs) [1][2][3][4][5][6][7][8][9] as well as the baryon-dark matter (DM) scattering and neutrino physics [10] in the high redshifted epoch.…”

“…−1 [3,18,19]. Here, P 10 is the deexcitation rate due to Lyα given by P 10 ≈ 1.3×10 −21 S α J −21 s −1 where C 10 is the collision deexcitation rate, S α is the spectral distortion factor [20] and J −21 represents the Lyman-α background intensity [21].…”