General treatment of isocurvature perturbations and non-Gaussianities

Abstract

We present a general formalism that provides a systematic computation of the linear and non-linear perturbations for an arbitrary number of cosmological fluids in the early Universe going through various transitions, in particular the decay of some species (such as a curvaton or a modulus). Using this formalism, we revisit the question of isocurvature non-Gaussianities in the mixed inflaton-curvaton scenario and show that one can obtain significant non-Gaussianities dominated by the isocurvature mode while satisfying the present constraints on the isocurvature contribution in the observed power spectrum. We also study two-curvaton scenarios, taking into account the production of dark matter, and investigate in which cases significant non-Gaussianities can be produced.

Substantial improvements with respect to the first version. In particular, we added a discussion on the confrontation of the models with future observational data. This version is accepted for publication in JCAP

References in corpus (12)

• Correlated isocurvature perturbations from mixed inflaton-curvaton decay
• Primordial non-Gaussianity from two curvaton decays
• Isocurvature, non-gaussianity and the curvaton model
• Limits on Isocurvature Perturbations from Non-Gaussianity in WMAP Temperature Anisotropies
• Primordial perturbations and non-Gaussianities from modulated trapping
• Non-Gaussianity from Baryon Asymmetry
• N-vaton
• Primordial Non-Gaussianity in Models with Dark Matter Isocurvature Fluctuations
• Nonlinear perturbations for dissipative and interacting relativistic fluids
• Neutralino Dark Matter and the Curvaton
• Multiple scalar particle decay and perturbation generation
• Curvaton Decay into Baryons, anti-Baryons and Radiation

Cited by in corpus (11)

• Non-Gaussian Stochastic Gravitational Waves from Phase Transitions
• Hidden axion dark matter decaying through mixing with QCD axion and the 3.5 keV X-ray line
• Primordial Trispectrum from Isocurvature Fluctuations
• Elementary Theorems Regarding Blue Isocurvature Perturbations
• CMB hemispherical asymmetry from non-linear isocurvature perturbations
• Non-Gaussian Shape Discrimination with Spectroscopic Galaxy Surveys
• Refined Study of Isocurvature Fluctuations in the Curvaton Scenario
• Thermal Effects and Sudden Decay Approximation in the Curvaton Scenario
• Isocurvature modes: joint analysis of the CMB power spectrum and bispectrum
• Smooth hybrid inflation in a supersymmetric axion model
• An Analytic Treatment of Underdamped Axionic Blue Isocurvature Perturbations