Non-Gaussian isocurvature perturbations in dark radiation
arXiv:1202.4890 · doi:10.1088/1475-7516/2012/07/037
Abstract
We study non-Gaussian properties of the isocurvature perturbations in the dark radiation, which consists of the active neutrinos and extra light species, if exist. We first derive expressions for the bispectra of primordial perturbations which are mixtures of curvature and dark radiation isocurvature perturbations. We also discuss CMB bispectra produced in our model and forecast CMB constraints on the nonlinearity parameters based on the Fisher matrix analysis. Some concrete particle physics motivated models are presented in which large isocurvature perturbations in extra light species and/or the neutrino density isocurvature perturbations as well as their non-Gaussianities may be generated. Thus detections of non-Gaussianity in the dark radiation isocurvature perturbation will give us an opportunity to identify the origin of extra light species and lepton asymmetry.
32 pages, 7 figures
References in corpus (24)
- Report of the Dark Energy Task Force
- Cosmology seeking friendship with sterile neutrinos
- Sterile neutrinos with eV masses in cosmology -- how disfavoured exactly?
- Probing String Theory with Modulated Cosmological Fluctuations
- Signatures of a hidden cosmic microwave background
- Thermal axion production in the primordial quark-gluon plasma
- Fast Estimator of Primordial Non-Gaussianity from Temperature and Polarization Anisotropies in the Cosmic Microwave Background
- Non-Thermal Dark Matter Mimicking An Additional Neutrino Species In The Early Universe
- Non-gaussianity and cosmic uncertainty in curvaton-type models
- Dark Radiation Emerging After Big Bang Nucleosynthesis?
- A theory of extra radiation in the Universe
- Study of the Experimental Probe of Inflationary Cosmology (EPIC)-Intemediate Mission for NASA's Einstein Inflation Probe
- Dark Radiation from Particle Decays during Big Bang Nucleosynthesis
- Ultra-light Axions: Degeneracies with Massive Neutrinos and Forecasts for Future Cosmological Observations
- Limits on Isocurvature Perturbations from Non-Gaussianity in WMAP Temperature Anisotropies
- Probing the Effective Number of Neutrino Species with Cosmic Microwave Background
- Non-Gaussianity from Symmetry
- Non-Gaussianity from Baryon Asymmetry
- Light Higgsino from Axion Dark Radiation
- General treatment of isocurvature perturbations and non-Gaussianities
- Bino Dark Matter and Big Bang Nucleosynthesis in the Constrained E6SSM with Massless Inert Singlinos
- Future constraints on neutrino isocurvature perturbations in the curvaton scenario
- Dark Radiation from Modulated Reheating
- Primordial Trispectrum from Isocurvature Fluctuations
Cited by in corpus (14)
- Planck 2015 results. XVII. Constraints on primordial non-Gaussianity
- Planck 2018 results. IX. Constraints on primordial non-Gaussianity
- Dark radiation from particle decay: cosmological constraints and opportunities
- Probing dark radiation with inflationary gravitational waves
- CMB constraint on non-Gaussianity in isocurvature perturbations
- Isocurvature modes in the CMB bispectrum
- Anisotropic CMB distortions from non-Gaussian isocurvature perturbations
- Extended analysis of CMB constraints on non-Gaussianity in isocurvature perturbations
- BBN constraints on dark radiation isocurvature
- Isocurvature modes: joint analysis of the CMB power spectrum and bispectrum
- Smooth hybrid inflation in a supersymmetric axion model
- Generalized neutrino isocurvature
- Cosmological perturbation theory with trinity of scalar fields
- Non-Gaussianity in Cosmology: from Inflation to the CMB