相关论文: CMB and BBN constraints on evaporating primordial …
We revisit cosmic microwave background (CMB) constraints on primordial black hole dark matter. Spectral distortion limits from COBE/FIRAS do not impose a relevant constraint. Planck CMB anisotropy power spectra imply that primordial black…
Possible influence of primordial black hole (PBH) evaporations on cosmic microwave background (CMB) is investigated. The spectrum distortions of CMB from the black-body spectrum are described by the chemical potential $\mu$ and the Compton…
The accretion of matter onto primordial black holes (PBHs) during the dark ages and the subsequent energy injection in the medium should have left imprints on the cosmic microwave background (CMB) anisotropies. Recent works have claimed…
We calculate the spectral distortions from Hawking evaporation of primordial black holes before the epoch of recombination, taking into account emission of all standard model particles, including quark and gluons, and evolving the resulting…
We examine the effects ultra-light primordial black holes (PBHs) have on the anisotropies of the cosmic microwave background (CMB). PBHs in the mass range of $10^{15}$ to $10^{17}$ g emit Hawking radiation in the early Universe, modifying…
We consider the imprint of superradiant instabilities of nonevaporating primordial black holes (PBHs) on the spectrum of the cosmic microwave background (CMB). In the radiation dominated era, PBHs are surrounded by a roughly homogeneous…
We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. These constraints are very powerful around or just after…
If present in the early universe, primordial black holes (PBHs) will accrete matter and emit high-energy photons, altering the statistical properties of the {Cosmic Microwave Background (CMB)}. This mechanism has been used to constrain the…
Primordial black holes (PBHs) are considered viable candidates for dark matter and the seeds of supermassive black holes (SMBHs), with their fruitful physical influences providing significant insights into the conditions of the early…
We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range $10^{-5}\text{--}10^{50}$ g. Those smaller than $\sim 10^{15}$ g would have evaporated by now due to Hawking…
Injection of high energy electromagnetic particles around the recombination epoch can modify the standard recombination history and therefore the CMB anisotropy power spectrum. Previous studies have put strong constraints on the amount of…
Stellar-mass Primordial Black Holes (PBH) have been recently reconsidered as a Dark Matter (DM) candidate, after the aLIGO discovery of several binary BH mergers with masses of tens of $M_\odot$. Matter accretion on such massive objects…
Current observational data favor cosmological models which differ from the standard model due to the presence of some form of dark energy and, perhaps, by additional contributions to the more familiar dark matter. Primordial nucleosynthesis…
Spectral distortions of the cosmic microwave background (CMB) provide stringent constraints on energy and entropy production in the post-BBN (Big Bang Nucleosynthesis) era. This has been used to constrain dark photon models with COBE/FIRAS…
As space expands, the energy density in black holes increases relative to that of radiation, providing us with motivation to consider scenarios in which the early universe contained a significant abundance of such objects. In this study, we…
It has recently been proposed that massive primordial black holes (PBH) could constitute all of the dark matter, providing a novel scenario of structure formation, with early reionization and a rapid growth of the massive black holes at the…
Observations of the cosmic microwave background constrain the abundance of primordial black holes, as these would accrete gas and inject energy into the cosmological medium. We have revisited these constraints, taking into account the local…
Many inflation theories predict that the primordial power spectrum is scale invariant. The amplitude of the power spectrum can be constrained by different observations such as the cosmic microwave background (CMB), Lyman-$\alpha$,…
We propose a new mechanism for the formation of seeds of supermassive black holes at early cosmic epochs. Enhanced density fluctuations with amplitudes that are not large enough to form primordial black holes post-inflation can still lead…
We investigate constraints on the abundance of primordial black holes (PBHs) in the mass range 10^{15}-10^{17} g using data from the Cosmic Microwave Background (CMB) and MeV extragalactic gamma-ray background (EGB). Hawking radiation from…