Related papers: Constraints on the small scale curvature perturbat…
Recently, a new framework for solving the hierarchy problem was proposed which does not rely on low energy supersymmetry or technicolor. The fundamental Planck mass is at a TeV and the observed weakness of gravity at long distances is due…
We investigate constraints on the least explored, smallest mass scales of primordial black holes (PBHs), which evaporate prior to Big Bang Nucleosynthesis (BBN). Our study examines the impact of Planck-mass relics on the allowed fraction of…
Primordial black holes (PBHs) can be both candidates of dark matter and progenitors of binary black holes (BBHs) detected by the LIGO-Virgo-KAGRA collaboration. Since PBHs could form in the very early Universe through the gravitational…
The existence (and abundance) of primordial black holes (PBHs) is governed by the power spectrum of primordial perturbations generated during inflation. So far no PBHs have been observed, and instead, increasingly stringent bounds on their…
The phenomenology of primordial black hole (PBH) physics and the associated PBH abundance constraints, can be used in order to probe the physics of the early Universe. In this work, we investigate the PBH formation during the standard…
We derive robust constraints on the initial abundance of evaporating primordial black holes (PBHs) using the reionization history of the Universe as a cosmological probe. We focus on PBHs that inject electromagnetic (EM) energy into the…
Primordial black hole (PBH) abundance limits constrain the primordial power spectrum, and hence models of inflation, on scales far smaller than those probed by cosmological observations. Single field inflation models which are compatible…
The computation of PBH (primordial black hole) production from primordial perturbations has recently been improved by considering a more accurate relation between the primordial power spectrum and the PBH mass variance. We present here…
We calculate the constraints on the primordial curvature perturbation at the end of inflation from the present day abundance of Primordial Black Holes (PBHs), as a function of the reheat temperature T_{\rm RH}. We first extend recent work…
Within the mass range of $10^{16}-5\times 10^{18}$ g, primordial black holes (PBHs) persist as plausible candidates for dark matter. Our study involves a reassessment of the constraints on PBHs through a comparative analysis of the cosmic…
Any variation of the fundamental physical constants, and more particularly of the fine structure constant, $\alpha$, or of the mass of the electron, $m_e$, would affect the recombination history of the Universe and cause an imprint on the…
We investigate the spectral shape of a high-energy diffuse photon emitted by evaporating primordial black holes (PBHs) in the Randall-Sundrum type II (RS2) braneworld. In their braneworld scenario, the nature of small PBHs is drastically…
In the mixed dark matter scenarios consisting of primordial black holes (PBHs) and weakly interacting massive particles (WIMPs), WIMPs can be accreted onto PBHs to form ultracompact minihalos (UCMHs) with a density spike in the early…
The presence of magnetic fields in the early universe affects the cosmological processes, leading to the distinct signature, which allows constraining their properties and the genesis mechanisms. In this study, we revisit the method to…
Primordial Black Holes (PBHs) may have been created by density fluctuations in the early Universe and could be as massive as $> 10^9$ solar masses or as small as the Planck mass. It has been postulated that a black hole has a temperature…
While Primordial Black Holes (PBHs) with masses $M_{\rm PBH} \gtrsim 10^{-11} \, M_\odot$ cannot comprise the entirety of dark matter, the existence of even a small population of these objects can have profound astrophysical consequences. A…
The possibility that the dark matter comprises primordial black holes (PBHs) is considered, with particular emphasis on the currently allowed mass windows at $10^{16}$ - $10^{17}\,$g, $10^{20}$ - $10^{24}\,$g and $1$ - $10^{3}\,M_{\odot}$.…
Cascade of particles injected as Hawking Radiation from Primordial Black Holes (PBH) can potentially change the cosmic recombination history by ionizing and heating the intergalactic medium, which results in altering the anisotropy spectra…
Primordial black holes are unique probes of cosmology, general relativity, quantum gravity and non standard particle physics. They can be considered as the ultimate particle accelerator in their last (explosive) moments since they are…
Primordial black holes (PBH) may constitute a considerable fraction of dark matter. In this work we use the recent observations by the LIGO-Virgo-KAGRA (LVK) collaborations to set direct limits on stellar-mass range PBHs. We evaluate the…