Nonlinear long-wavelength solutions are constructed for cosmological perturbations in non-adiabatic multi-fluid systems, admitting adiabatic and entropy modes at leading order via ADM and gradient expansion.
Primordial black hole formation from massless scalar isocurvature
3 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
We numerically study the primordial black hole (PBH) formation by an isocurvature perturbation of a massless scalar field on super Hubble scales in the radiation-dominated universe. As a first step we perform simulations of spherically symmetric configurations. For the initial condition, we employ the spatial gradient expansion and provide the general form of the growing mode solutions valid up through the second order in this expansion. The initial scalar field profile is assumed to be Gaussian with a characteristic comoving wavenumber $k$; $\sim\exp(-k^2R^2)$, where $R$ is the radial coordinate. We find that a PBH is formed for a sufficiently large amplitude of the scalar field profile. Nevertheless, we find that the late time behavior of the gravitational collapse is dominated by the dynamics of the fluid but not by the scalar field, which is analogous to the PBH formation from an adiabatic perturbation in the radiation-dominated universe.
representative citing papers
Shape dispersion around the average peak profile is a genuine statistical ingredient: rare deformed curvature profiles can dominate primordial black hole formation when the power spectrum is broad or non-Gaussianity is negative.
Bulk viscosity raises the critical collapse threshold for primordial black holes by an amount comparable to the viscosity strength and increases the resulting black hole masses.
citing papers explorer
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Cosmological long-wavelength solutions in non-adiabatic multi-fluid systems
Nonlinear long-wavelength solutions are constructed for cosmological perturbations in non-adiabatic multi-fluid systems, admitting adiabatic and entropy modes at leading order via ADM and gradient expansion.
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The statistics of curvature-profile dispersion in primordial black hole formation
Shape dispersion around the average peak profile is a genuine statistical ingredient: rare deformed curvature profiles can dominate primordial black hole formation when the power spectrum is broad or non-Gaussianity is negative.
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Primordial black hole formation in bulk-viscous cosmology
Bulk viscosity raises the critical collapse threshold for primordial black holes by an amount comparable to the viscosity strength and increases the resulting black hole masses.