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arXiv · 1007.5498

General treatment of isocurvature perturbations and non-Gaussianities

David Langlois·Angela Lepidi
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Abstract

We present a general formalism that provides a systematic computation of the linear and non-linear perturbations for an arbitrary number of cosmological fluids in the early Universe going through various transitions, in particular the decay of some species (such as a curvaton or a modulus). Using this formalism, we revisit the question of isocurvature non-Gaussianities in the mixed inflaton-curvaton scenario and show that one can obtain significant non-Gaussianities dominated by the isocurvature mode while satisfying the present constraints on the isocurvature contribution in the observed power spectrum. We also study two-curvaton scenarios, taking into account the production of dark matter, and investigate in which cases significant non-Gaussianities can be produced.

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David Langlois, Angela Lepidi. 2010-07-30. General treatment of isocurvature perturbations and non-Gaussianities. https://doi.org/10.1088/1475-7516/2011/01/008

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