Primordial non-Gaussianity from two curvaton decays

Abstract

We study a model where two scalar fields, that are subdominant during inflation, decay into radiation some time after inflation has ended but before primordial nucleosynthesis. Perturbations of these two curvaton fields can be responsible for the primordial curvature perturbation. We write down the full non-linear equations that relate the primordial perturbation to the curvaton perturbations on large scales, calculate the power spectrum of the primordial perturbation, and finally go to second order to find the non-linearity parameter, fNL. We find large positive values of fNL if the energy densities of the curvatons are sub-dominant when they decay, as in the single curvaton case. But we also find a large fNL even if the curvatons dominate the total energy density in the case when the inhomogeneous radiation produced by the first curvaton decay is diluted by the decay of a second nearly homogeneous curvaton. The minimum value min(fNL)=-5/4 which we find is the same as in the single-curvaton case.

20 pages, 5 figures

References in corpus (34)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Generating the curvature perturbation without an inflaton
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• Adiabatic CMB perturbations in pre-big bang string cosmology
• Effects of Cosmological Moduli Fields on Cosmic Microwave Background
• A general proof of the conservation of the curvature perturbation
• The primordial density perturbation in the curvaton scenario
• Nongaussian Isocurvature Perturbations from Inflation
• Second-Order Cosmological Perturbations from Inflation
• The inflationary prediction for primordial non-gaussianity
• Non-Gaussianity of the primordial perturbation in the curvaton model
• Primordial non-gaussianities from multiple-field inflation
• An Observational Test of Two-field Inflation
• Primordial trispectrum from inflation
• The General Primordial Cosmic Perturbation
• The Separate Universe Approach and the Evolution of Nonlinear Superhorizon Cosmological Perturbations
• The inflationary trispectrum
• Conserved cosmological perturbations
• Non-Gaussianity in Curvaton Models with Nearly Quadratic Potential
• The simplest curvaton model
• A numerical study of non-gaussianity in the curvaton scenario
• Conserved non-linear quantities in cosmology
• Constraining Isocurvature Initial Conditions with WMAP 3-year data
• Gauge-Invariant Temperature Anisotropies and Primordial Non-Gaussianity
• Non-gaussianity from the inflationary trispectrum
• Limits on isocurvature fluctuations from Boomerang and MAXIMA
• Non-Gaussian perturbations in hybrid inflation
• Correlated isocurvature perturbations from mixed inflaton-curvaton decay
• The isocurvature fraction after WMAP 3-year data
• Hints of Isocurvature Perturbations in the Cosmic Microwave Background?
• Primordial non-Gaussianity and Dark Energy constraints from Cluster Surveys
• Multiple scalar particle decay and perturbation generation
• Nonlinear curvature perturbations in an exactly soluble model of multi-component slow-roll inflation

Cited by in corpus (52)

• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Enhanced Non-Gaussianity from Excited Initial States
• Non-Gaussianity in the modulated reheating scenario
• Signatures of Initial State Modifications on Bispectrum Statistics
• Review of local non-Gaussianity from multi-field inflation
• Gravitational waves from an early matter era
• Structure formation from non-Gaussian initial conditions: multivariate biasing, statistics, and comparison with N-body simulations
• Detectability of the effect of Inflationary non-Gaussianity on halo bias
• Local non-Gaussianity from inflation
• Scale dependence of local f_NL
• Adiabatic initial conditions for perturbations in interacting dark energy models
• Signature of Primordial Non-Gaussianity on Matter Power Spectrum
• Primordial Non-Gaussianities of General Multiple Field Inflation
• On Classification of Models of Large Local-Type Non-Gaussianity
• Primordial Non-Gaussianity in the Cosmic Microwave Background
• Encyclopaedia Curvatonis
• The Subdominant Curvaton
• Primordial Trispectrum from Entropy Perturbations in Multifield DBI Model
• Distinguishing interacting dark energy from wCDM with CMB, lensing, and baryon acoustic oscillation data
• Limits on Isocurvature Perturbations from Non-Gaussianity in WMAP Temperature Anisotropies
• The clustering of galaxies and galaxy clusters: constraints on primordial non-Gaussianity from future wide-field surveys
• Comprehensive analysis of the simplest curvaton model
• Imprints of primordial non-Gaussianity on the number counts of cosmic shear peaks
• Non-Gaussianity from resonant curvaton decay
• Perturbative Reheating After Multiple-Field Inflation: The Impact on Primordial Observables
• N-vaton
• General treatment of isocurvature perturbations and non-Gaussianities
• Parametric Decay of the Curvaton
• Runnings in the Curvaton
• Baryon history and cosmic star formation in non-Gaussian cosmological models: numerical simulations
• Non-Gaussianities of Single Field Inflation with Non-minimal Coupling
• Modulated curvaton decay
• Density Perturbations from Modulated Decay of the Curvaton
• Searching for non-Gaussianity in the WMAP data
• Probing the Early Universe with the CMB Scalar, Vector and Tensor Bispectrum
• Fermionic Isocurvature Perturbations
• Non-Gaussianity in three fluid curvaton model
• Rescuing Quadratic Inflation
• Effect of reheating on predictions following multiple-field inflation
• Temporal enhancement of super-horizon curvature perturbations from decays of two curvatons and its cosmological consequences
• Curvaton and the inhomogeneous end of inflation
• New features in curvaton model
• Non-Gaussianity and gravitational wave background in curvaton with a double well potential
• The effect of primordial non-Gaussianity on the skeleton of cosmic shear maps
• Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion
• The Effect of Curvaton Decay on the Primordial Power Spectrum
• Non-Gaussianity from two right-handed sneutrino curvaton decays
• Mixed perturbations from an Inflaton and Two Curvatons - towards understanding non-gaussianity in more complicated curvaton scenarios
• Curvaton decay into relativistic matter
• Spectator fields and their imprints on the Cosmic Microwave Background
• Non-Gaussianity after many-field reheating
• Construction and applications of the manifestly gauge invariant expressions of the solutions of the cosmological perturbation theory