Related papers: Complex Scalar Field Reheating and Primordial Blac…
Scalar fields are ubiquitous in theories of high-energy physics. In the context of cosmic inflation, this suggests the existence of spectator fields, which provide a subdominant source of energy density. We show that spectator fields boost…
The Hawking evaporation of primordial black holes (PBH) reheats the Universe locally, forming hot spots that survive throughout their lifetime. We propose to use the temperature profile of such hot spots to calculate the decay rate of…
Recent developments in the study of primordial black holes (PBHs) will be reviewed, with particular emphasis on their formation and evaporation. PBHs could provide a unique probe of the early Universe, gravitational collapse, high energy…
Cosmological perturbations, originating in the quantum fluctuations of the fields that drive inflation, are observed to be nearly scale invariant at the largest scales. At smaller scales, however, perturbations are not severely constrained…
This paper examines the interaction of an intense fermion field with all of the particle species of an attometer primordial black hole's (PBH)'s high energy Hawking radiation spectrum. By extrapolating to Planck-sized PBH's, it is shown…
The final mass distribution of primordial black holes is sensitive to the equation of state of the Universe at the scales accessible by the power spectrum. Motivated by the presence of phase transitions in several beyond the Standard Model…
We consider the formation of horizon-size primordial black holes (PBH's) from pre-existing density fluctuations during cosmic phase transitions. It is pointed out that the formation of PBH's should be particularly efficient during the QCD…
Primordial Black Holes (PBHs) may form in the early Universe, from the gravitational collapse of large density perturbations, generated by large quantum fluctuations during inflation. Since PBHs form from rare over-densities, their…
[Abridged] The primordial scalar power spectrum is well constrained on large scales, primarily by the observations of the anisotropies in the cosmic microwave background (CMB). Over the last few years, it has been recognized that a sharp…
We demonstrate that violent kinetic preheating following inflation can lead to the formation of black holes in the early Universe. In $\alpha$-attractor models with derivative inflaton couplings, nonlinear amplification of field…
Primordial Black Holes (PBH) arise naturally from high peaks in the curvature power spectrum of near-inflection-point single-field inflation, and could constitute today the dominant component of the dark matter in the universe. In this…
We in this paper investigate the formation and evolution of primordial black holes (PBHs) in nonsingular bouncing cosmologies. We discuss the formation of PBH in the contracting phase and calculate the PBH abundance as a function of the…
We discuss the possibility that dark matter corresponds to an oscillating scalar field coupled to the Higgs boson. We argue that the initial field amplitude should generically be of the order of the Hubble parameter during inflation, as a…
We revisit the scenario of primordial black hole (PBH) formation from large curvature perturbations generated during the waterfall phase transition in hybrid inflation models. In a minimal setup considered in the literature, the mass and…
General expressions are given for the generation of Primordial Black Holes (PBH) in a universe with a presently accelerated expansion due to a(n effective) cosmological constant. We give expressions both for a powerlaw scalefree primordial…
We investigate the dynamics of the perturbations of the inflaton scalar field oscillating around a minimum of its effective potential in an expanding universe. With the assumption of smallness of the ratio of the Hubble parameter to the…
In order to produce appreciable amount of primordial black holes (PBHs), the square amplitude of curvature perturbation must take a large value of $\mathcal{O}(0.01)$, namely, seven digits larger than the value observed by cosmic microwave…
Primordial Black Holes (PBHs) can form in the radiation dominated early Universe from the collapse of large density perturbations produced by inflation. A power-law parameterisation of the primordial power spectrum is often used to…
We study scalar perturbations and quasinormal modes of a nonlinear magnetic charged black hole surrounded by quintessence. Time evolution of scalar perturbations is studied for different parameters associated with the black hole solution.…
We investigate the formation of primordial black holes (PBHs), their spin and abundance, in a single-field inflationary model based on a mutated hilltop potential inserted with a small step-like feature. This step induces a brief phase of…