Related papers: Prospects of Future CMB Anisotropy Probes for Prim…
Damping of magnetic fields via ambipolar diffusion and decay of magnetohydrodynamical (MHD) turbulence in the post decoupling era heats the intergalactic medium (IGM). Delayed recombination of hydrogen atoms in the IGM yields an optical…
Primordial black holes (PBHs) have been proposed to explain at least a portion of dark matter. Observations have put strong constraints on PBHs in terms of the fraction of dark matter which they can represent, $f_{\rm PBH}$, across a wide…
The presence of an extra radio background besides the cosmic microwave background has important implications for the observation of the 21-cm signal during the cosmic Dark Ages, Cosmic Dawn, and epoch of Reionization. The strong absorption…
The particles emitted from PBHs through the Hawking radiation have interactions with the particles present in the Universe. Due to the interactions, the evolution of the intergalactic medium (IGM) is changed and the changes have imprints on…
I describe briefly the Cosmic Microwave Background (hereafter CMB) physics which explains why high accuracy observations of its spatial structure are a unique observational tool both for the determination of the global cosmological…
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 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 particles. The variations of the thermal history of…
Baryonic gas falling onto a primordial black hole (PBH) emits photons via the free-free process. These photons can contribute the diffuse free-free background radiation in the frequency range of the cosmic microwave background radiation…
Primordial Black Holes (PBHs) in the mass range $\sim 10^{17}- 10^{22}$g are currently unconstrained, and can constitute the full Dark Matter (DM) density of the universe. Motivated by this, in the current work, we aim to relate the…
We study the possibility of reheating the universe in its early stages through the evaporation of Primordial Black Holes (PBHs) that are formed due to the collapse of the inhomogeneities that were generated during inflation. By using the…
We derive updated Cosmic Microwave Background (CMB) constraints on annihilating dark matter, and present forecasts for upcoming CMB surveys. We show that the addition of recent temperature, polarization, and lensing data from ground-based…
Primordial black holes (PBHs), hypothesized to form in the early universe from gravitational collapse of density fluctuations, represent a well-motivated dark matter (DM) candidate. Their potential detection through gamma-ray signatures…
Diffusion damping of the cosmic microwave background (CMB) power spectrum results from imperfect photon-baryon coupling in the pre-recombination plasma. At redshift $5 \times 10^4 < z < 2 \times 10^6$, the plasma acquires an effective…
The intermediate mass black hole range, $10\lesssim M_{\rm BH}^{}/M_\odot^{}\lesssim 10^{5} $, has long offered enticing possibilities for primordial black holes (PBH), with populations in this range postulated to be responsible for some of…
Measurements of the cosmic microwave background (CMB) spectral distortions (SDs) will open a new window on the very early universe, providing new information complementary to that gathered from CMB temperature and polarization anisotropies.…
Primordial black holes (PBHs) are theoretical black holes which may be formed during the radiation dominant era and, basically, caused by the gravitational collapse of radiational overdensities. It has been well known that in the context of…
In the model where Primordial Black Holes (PBHs) form from large primordial curvature (C) perturbations, i.e., CPBHs, constraints on PBH abundance provide in principle constraints on the primordial curvature power spectrum. This connection…
Recent measurements of the cosmic X-ray and radio backgrounds (CXB/CRB, respectively) obtained with Chandra and ARCADE2 report signals in excess of those expected from known sources, suggesting the presence of a yet undiscovered population…
The injection of secondary particles produced by Dark Matter (DM) annihilation at redshift 100<z<1000 affects the process of recombination, leaving an imprint on Cosmic Microwave Background (CMB) anisotropies. Here we provide a new…
Measurements of the cosmic microwave background (CMB) allow high precision observation of the Last Scattering Surface at redshift $z\sim$1100. After the success of the NASA satellite COBE, that in 1992 provided the first detection of the…