Comprehensive analysis of the simplest curvaton model

Abstract

We carry out a comprehensive analysis of the simplest curvaton model, which is based on two non-interacting massive fields. Our analysis encompasses cases where the inflaton and curvaton both contribute to observable perturbations, and where the curvaton itself drives a second period of inflation. We consider both power spectrum and non-Gaussianity observables, and focus on presenting constraints in model parameter space. The fully curvaton-dominated regime is in some tension with observational data, while an admixture of inflaton-generated perturbations improves the fit. The inflating curvaton regime mimics the predictions of Nflation. Some parts of parameter space permitted by power spectrum data are excluded by non-Gaussianity constraints. The recent BICEP2 results [1] require that the inflaton perturbations provide a significant fraction of the total perturbation, ruling out the usual curvaton scenario in which the inflaton perturbations are negligible, though not the admixture regime where both inflaton and curvaton contribute to the spectrum.

7 pages, 9 figures; v2 matches journal accepted version

References in corpus (11)

• BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales
• Non-Gaussianities in two-field inflation
• Non-Gaussianity, Spectral Index and Tensor Modes in Mixed Inflaton and Curvaton Models
• Scale-dependent non-Gaussianity probes inflationary physics
• Nflation: multi-field inflationary dynamics and perturbations
• Primordial non-Gaussianity from two curvaton decays
• On what scale should inflationary observables be constrained?
• First constraints on the running of non-Gaussianity
• Runnings in the Curvaton
• General analytic predictions of two-field inflation and perturbative reheating
• Nflation: observable predictions from the random matrix mass spectrum

Cited by in corpus (38)

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• Encyclopaedia Curvatonis
• Lighting the Dark: The Evolution of the Post-Inflationary Universe
• Observational implications of mattergenesis during inflation
• The challenge for single field inflation with BICEP2 result
• Inflation with an extra light scalar field after Planck
• The next non-Gaussianity frontier: what can a measurement with $\sigma (f_{\mathrm{NL}})\lesssim 1$ tell us about multifield inflation?
• New universal property of cosmological gravitational wave anisotropies
• Curvaton in large field inflation
• Modified Lyth bound and implications of BICEP2 results
• Measuring the duration of inflation with the curvaton
• Non-Gaussianity in multiple three-form field inflation
• Compensation for large tensor modes with iso-curvature perturbations in CMB anisotropies
• Chaotic inflation with curvaton induced running
• Bayesian evidence of the post-Planck curvaton
• CMB spectral distortions in generic two-field models
• Quantum collapse as source of the seeds of cosmic structure during the radiation era
• Radiative Corrections from Heavy Fast-Roll Fields during Inflation
• Primordial non-Gaussianity as a probe of seesaw and leptogenesis
• Non-Gaussianity in two-field inflation beyond the slow-roll approximation
• BICEP2, the curvature perturbation and supersymmetry
• Resolving primordial physics through correlated signatures
• Curvaton scenarios with inflaton decays into curvatons
• Revised $f_{\mathrm{NL}}$ parameter in Curvaton Scenario
• Thermal Effects and Sudden Decay Approximation in the Curvaton Scenario
• Radiative Inflation and Dark Energy RIDEs Again after BICEP2
• Primordial black holes from the ultraslow-roll phase in the inflaton--curvaton mixed field inflation
• Primordial black holes from a curvaton: the role of bimodal distributions
• Stabilising the Planck mass shortly after inflation
• Viable Curvaton Models from the $f_{NL}$ Parameter
• Curvaton: Perturbations and reheating
• Spectator fields and their imprints on the Cosmic Microwave Background
• Non-Gaussianity in Cosmology: from Inflation to the CMB
• Unified Origin of Curvature Perturbation and Baryon Asymmetry of the Universe
• Testing Inflationary Cosmology