Primordial trispectrum from isocurvature fluctuations

Journal Article · Tue Feb 01 04:00:00 EST 2011 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2011/02/020· OSTI ID:22275296

Langlois, David ^[1]; Takahashi, Tomo ^[2]

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1. APC (CNRS-Université Paris 7), 10, rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)
2. Department of Physics, Saga University, Saga 840-8502 (Japan)

We study non-Gaussianity generated by adiabatic and isocurvature primordial perturbations. We first obtain, in a very general setting, the non-linear perturbations, up to third order, for an arbitrary number of cosmological fluids, going through one or several decay transitions. We then apply this formalism to the mixed curvaton and inflaton model, allowing for several decay channels. We compute the various contributions to the bispectrum and trispectrum resulting from adiabatic and isocurvature perturbations, which are correlated in general. By investigating some hybrid decay scenario, we show that significant non-Gaussianity of adiabatic and isocurvature types can be generated without conflicting with the present isocurvature constraints from the power spectrum. In particular, we find cases where non-Gaussianity of isocurvature origin can dominate its adiabatic counterpart, both in the bispectrum and in the trispectrum.

• OSTI ID: 22275296
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 02 Vol. 2011; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMOLOGICAL MODELS
COSMOLOGY
DISTURBANCES
ENERGY SPECTRA
FLUCTUATIONS
LIMITING VALUES
NONLINEAR PROBLEMS