Non-Gaussianities in models with a varying inflaton decay rate

2003/05/30 by Matias Zaldarriaga, Matías Zaldarriaga · 7 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Ansatz #Cosmology and Gravitation Theories #Coupling (piping) #Field (mathematics) #Geophysics and Gravity Measurements #Inflation (cosmology) #Inflaton #Mathematical physics #Mathematics #Order (exchange) #Physics #Quantum mechanics #Solar and Space Plasma Dynamics #astro-ph

paper · pdf · doi:10.1103/physrevd.69.043508

published as Phys.Rev.D69:043508,2004

arxiv created 2003/05/30 · openalex publication_date 2004/02/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider non-Gaussianities resulting from the self-coupling of the field that controls the decay rate of the inflaton and non-Gaussianities resulting from the nonlinear relation between field and curvature perturbations. We show that in these scenarios non-Gaussianities are of the ``local'' form, i.e., well described by the ansatz R=R_g+f_NL^R(R_g²\ensuremath-〈R_g²〉). This is a consequence of the fact that they were created when modes were already outside the horizon. We show that f_NL^R is naturally of the order of a few in these models, much larger than what is expected in the standard one field models of inflation (f_NL^R\ensuremath∼10^\ensuremath-2) and possibly accessible to observations.

Citations

• Generating the curvature perturbation without an inflaton
• Inflationary models inducing non-Gaussian metric fluctuations
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• First‐Year Wilkinson Microwave Anisotropy Probe ( WMAP ) Observations: Preliminary Maps and Basic Results
• First‐Year Wilkinson Microwave Anisotropy Probe ( WMAP ) Observations: Determination of Cosmological Parameters

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• Non-Gaussianity and baryonic isocurvature fluctuations in the curvaton scenario
• On the generation of a non-gaussian curvature perturbation during preheating
• Combined local and equilateral non-Gaussianities from multifield DBI inflation
• Multi-disformal invariance of non-linear primordial perturbations