WMAP, neutrino degeneracy and non-Gaussianity constraints on isocurvature perturbations in the curvaton model of inflation

Abstract

In the curvaton model of inflation, where a second scalar field, the "curvaton", is responsible for the observed inhomogeneity, a non-zero neutrino degeneracy may lead to a characteristic pattern of isocurvature perturbations in the neutrino, cold dark matter and baryon components. We find the current data can only place upper limits on the level of isocurvature perturbations. These can be translated into upper limits on the neutrino degeneracy parameter. In the case that lepton number is created before curvaton decay, we find that the limit on the neutrino degeneracy parameter is comparable with that obtained from Big-bang nucleosynthesis. For the case that lepton number is created by curvaton decay we find that the absolute value of the non-Gaussianity parameter, |f_nl|, must be less than 10 (95% confidence interval).

8 pages. Minor changes to text, references added, matches version to appear in PRD

References in corpus (32)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Wilkinson Microwave Anisotropy Probe (WMAP) First Year Observations: TE Polarization
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Angular Power Spectrum
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Tests of Gaussianity
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Parameter Estimation Methodology
• High Resolution Observations of the CMB Power Spectrum with ACBAR
• Neutrino masses and the number of neutrino species from WMAP and 2dFGRS
• Conserved cosmological perturbations
• Observational constraints on the curvaton model of inflation
• The Curvaton as a Pseudo-Nambu-Goldstone Boson
• Curvaton Dynamics
• Curvaton Reheating in Non-oscillatory Inflationary Models
• Bounds on isocurvature perturbations from CMB and LSS data
• MSSM flat direction as a curvaton
• The CDM isocurvature perturbation in the curvaton scenario
• The curvaton scenario in supersymmetric theories
• The Curvaton Hypothesis and the eta-problem of Quintessential Inflation, with and without Branes
• Evolution of Second-Order Cosmological Perturbations and Non-Gaussianity
• Can the curvaton paradigm accommodate a low inflation scale?
• The Peccei-Quinn Field as Curvaton
• Curvaton reheating: an application to braneworld inflation
• Challenges in generating density perturbations from a fluctuating inflaton coupling
• Measuring the cosmological background of relativistic particles with WMAP
• Constraints on the cosmic neutrino background
• Resonant decay of flat directions
• Cosmic String from D-term Inflation and Curvaton
• MSSM curvaton in the gauge-mediated SUSY breaking
• Right-Handed Sneutrinos as Curvatons
• Curvatons in Supersymmetric Models
• The cosmological constant and general isocurvature initial conditions
• Cosmological density perturbations from perturbed couplings
• Curvaton Potential Terms, Scale-Dependent Perturbation Spectra and Chaotic Initial Conditions

Cited by in corpus (43)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Planck 2013 results. XXII. Constraints on inflation
• CMB-S4 Science Case, Reference Design, and Project Plan
• Signatures of Relativistic Neutrinos in CMB Anisotropy and Matter Clustering
• Enhanced Non-Gaussianity from Excited Initial States
• A Low CMB Quadrupole from Dark Energy Isocurvature Perturbations
• Constraining Isocurvature Initial Conditions with WMAP 3-year data
• Bayesian model selection and isocurvature perturbations
• Large Nongaussianity from Nonlocal Inflation
• Constraints on a mixed inflaton and curvaton scenario for the generation of the curvature perturbation
• Cosmological lepton asymmetry with a nonzero mixing angle θ_{13}
• Constraints on isocurvature models from the WMAP first-year data
• Correlated isocurvature perturbations from mixed inflaton-curvaton decay
• The initial conditions of the universe: how much isocurvature is allowed?
• Bounds on CDM and neutrino isocurvature perturbations from CMB and LSS data
• Squeezing the window on isocurvature modes with the Lyman-alpha forest
• Isocurvature, non-gaussianity and the curvaton model
• Predictions for Nongaussianity from Nonlocal Inflation
• The Subdominant Curvaton
• Constraints on primordial isocurvature perturbations and spatial curvature by Bayesian model selection
• Non-Gaussianity from resonant curvaton decay
• CMB constraint on non-Gaussianity in isocurvature perturbations
• Parametric Decay of the Curvaton
• Constraints on scalar and tensor perturbations in phenomenological and two-field inflation models: Bayesian evidences for primordial isocurvature and tensor modes
• Measuring the geometry of the Universe in the presence of isocurvature modes
• Future constraints on neutrino isocurvature perturbations in the curvaton scenario
• Optimizing future experimental probes of inflation
• Conditions for a Successful Right-Handed Majorana Sneutrino Curvaton
• Constraints on neutrino density and velocity isocurvature modes from WMAP-9 data
• Curvaton Scenario with Affleck-Dine Baryogenesis
• Constraints on moduli cosmology from the production of dark matter and baryon isocurvature fluctuations
• Suppressing Super-Horizon Curvature Perturbations?
• Probing a panoply of curvaton-decay scenarios using CMB data
• On the Effects due to a Decaying Cosmological Fluctuation
• Extended analysis of CMB constraints on non-Gaussianity in isocurvature perturbations
• Nonlinear curvature perturbations in an exactly soluble model of multi-component slow-roll inflation
• Particle Physics Approach to Dark Matter
• Curvaton Decay into Baryons, anti-Baryons and Radiation
• Planck constraints on neutrino isocurvature density perturbations
• Cosmological Perturbations During Radion Stabilization
• Density perturbations from both the inflaton and the curvaton
• Probing Lepton Asymmetry with 21 cm Fluctuations
• CMB lensing forecasts for constraining the primordial perturbations: adding to the CMB temperature and polarization information