Related papers: Primordial Black Hole Formation in Starobinsky's L…
This paper is a biased review of primordial black hole (PBH) formation and abundance estimation. We first review the three-zone model for PBH formation to help an intuitive understanding of the PBH formation process. Then, for more accurate…
Observational constraints on the abundance of primordial black holes (PBHs) constrain the allowed amplitude of the primordial power spectrum on both the smallest and the largest ranges of scales, covering over 20 decades from $1-10^{20}/…
As one of the promising candidates of cold dark matter (DM), primordial black holes (PBHs) were formed due to the collapse of over-densed regions generated by the enhanced curvature perturbations during the radiation-dominated era. The…
The standard deviation of the initial values of the nondimensional Kerr parameter $a_{*}$ of primordial black holes (PBHs) formed in the radiation-dominated phase of the universe is estimated to the first order of perturbation for the…
We study the effect on the primordial tensor power spectrum of varying the number of e-folds during slow-roll inflation in Loop Quantum Cosmology with a Starobinsky potential. Using the hybrid quantization approach, we derive the effective…
We study the formation of primordial black holes (PBH) with ultra-slow-roll inflation when stochastic effects are important. We use the $\Delta N$ formalism and simplify the stochastic equations with an analytical constant-roll…
Cosmological $\alpha$-attractors stand out as particularly compelling models to describe inflation in the very early universe, naturally meeting tight observational bounds from cosmic microwave background (CMB) experiments. We investigate…
We performed the detailed analysis of the primordial black hole (PBH) formation mechanism in an axionlike curvaton model with a coupling to inflaton. The phase direction of the complex scalar works as a curvaton and produces enough PBHs to…
The one-loop corrections (1LC) to the power spectrum of scalar perturbations arising from cubic interactions in the single-field E-type $\alpha$-attractor models of inflation and primordial black hole (PBH) production are numerically…
Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the…
We perform a Markov Chain Monte Carlo (MCMC) analysis of a simple yet generic multifield inflation model characterized by two scalar fields coupled to each other and nonminimally coupled to gravity, fit to Planck 2018 cosmic microwave…
We investigate the phenomenology of a Standard Model extension incorporating an inert scalar doublet and a gauged $U(1)_{B-L}$ symmetry. Our analysis reveals regions of the parameter space that support strong first-order phase transitions,…
Primordial Black Holes (PBHs) have entered the forefront of theoretical cosmology, due their potential role in phenomena ranging from gravitational waves, to dark matter, to galaxy formation. While producing PBHs from inflationary…
If the inflaton gets trapped in a local minimum of its potential shortly before the end of inflation, it escapes by building up quantum fluctuations in a process known as stochastic tunnelling. In this work we study cosmological…
We investigate features of Gravitational Waves (GWs) induced by primordial density fluctuations with a large amplitude peak associated with formation of Primordial Black Holes (PBHs). It is shown that the spectrum of induced GW is…
Primordial Black Holes could be an important component of the dark matter in the Universe. If they exist, they would add a Poisson component to the matter power spectrum. The extra power would speed up the emergence of dark matter halos…
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…
We propose a novel method to probe primordial gravitational waves by means of primordial black holes (PBHs). When the amplitude of primordial tensor perturbations on comoving scales much smaller than those relevant to Cosmic Microwave…
We consider the possibility of primordial black hole, PBH, formation sourced by a rise in the power spectrum. The power spectrum becomes large at late times due to decay of the inflaton into vectors through a $\phi F \tilde{F}$ coupling.…
Primordial black holes (PBHs) generated in the early Universe are considered as one of the candidates for dark matter. To produce PBHs with sufficient abundance, the primordial scalar power spectrum needs to be enhanced to the order of…