Extends diagrammatic approach for scalar-induced gravitational waves to arbitrary-order local PNG, deriving semi-analytic spectra for energy density, anisotropies, bispectrum and trispectrum up to quartic terms.
Inflationary primordial black holes for the LIGO gravitational wave events and pulsar timing array experiments
5 Pith papers cite this work. Polarity classification is still indexing.
abstract
Primordial black holes (PBHs) are one of the candidates to explain the gravitational wave (GW) signals observed by the LIGO detectors. Among several phenomena in the early Universe, cosmic inflation is a major example to generate PBHs from large primordial density perturbations. In this paper, we discuss the possibility to interpret the observed GW events as mergers of PBHs which are produced by cosmic inflation. The primordial curvature perturbation should be large enough to produce a sizable amount of PBHs and thus we have several other probes to test this scenario. We point out that the current pulsar timing array (PTA) experiments already put severe constraints on GWs generated via the second-order effects, and that the observation of the cosmic microwave background (CMB) puts severe restriction on its $\mu$ distortion. In particular, it is found that the scalar power spectrum should have a very sharp peak at $k \sim 10^{6}$ Mpc$^{-1}$ to fulfill the required abundance of PBHs while evading constraints from the PTA experiments together with the $\mu$ distortion. We propose a mechanism which can realize such a sharp peak. In the future, simple inflation models that generate PBHs via almost Gaussian fluctuations could be probed/excluded.
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citation-polarity summary
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UNVERDICTED 5roles
background 4polarities
background 4representative citing papers
Torsion-induced fermion condensate produces hybrid inflation with axial-chemical-potential waterfall, Q-ball PBH seeds, and parity-violating signatures in Chern-Simons gravity.
Forecasts show that adding FAST/SKA upper or lower limits on scalar-induced GWs to CMB+BAO data shifts the scalar spectral index ns by several sigma in LambdaCDM+r and extended models, offering a potential detection indicator.
Primordial black holes in specific mass ranges could account for some or all dark matter while resolving structure-formation and seed problems in standard cosmology.
A review that unifies analytical expressions for scalar-induced gravitational waves and emphasizes calculations for non-radiation-dominated cosmologies.
citing papers explorer
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Isotropy, anisotropies and non-Gaussianity in the scalar-induced gravitational-wave background: diagrammatic approach for primordial non-Gaussianity up to arbitrary order
Extends diagrammatic approach for scalar-induced gravitational waves to arbitrary-order local PNG, deriving semi-analytic spectra for energy density, anisotropies, bispectrum and trispectrum up to quartic terms.
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Fermion Condensate Inflation, Dynamical Waterfall Mechanism and Primordial Black Holes
Torsion-induced fermion condensate produces hybrid inflation with axial-chemical-potential waterfall, Q-ball PBH seeds, and parity-violating signatures in Chern-Simons gravity.
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Probing the scalar-induced gravitational waves with the Five-hundred-meter Aperture Spherical radio Telescope and the Square Kilometer Array
Forecasts show that adding FAST/SKA upper or lower limits on scalar-induced GWs to CMB+BAO data shifts the scalar spectral index ns by several sigma in LambdaCDM+r and extended models, offering a potential detection indicator.
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Primordial Black Holes as Dark Matter: Recent Developments
Primordial black holes in specific mass ranges could account for some or all dark matter while resolving structure-formation and seed problems in standard cosmology.
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Scalar induced gravitational waves review
A review that unifies analytical expressions for scalar-induced gravitational waves and emphasizes calculations for non-radiation-dominated cosmologies.