Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Very Large Primordial Non-Gaussianity from multi-field
T2 - Application to Massless Preheating
AU - Jokinen, Asko
AU - Mazumdar, Anupam
N1 - 23 pages, JHEP style, references added
PY - 2006/4/6
Y1 - 2006/4/6
N2 - In this paper we derive a generic expression, which is valid for scales larger than Hubble radius and contains only the local terms, for the second order curvature perturbations for more than one field, provided the expansion is sourced by the energy density of a single field. As an application, motivated by our previous paper [1], we apply our formalism to two fields during preheating, where the inflaton oscillations are sourced by $\lambda\phi^4$ potential which is governing the expansion of the Universe. A second field $\sigma$, coupled to the inflaton through $g^2\phi^2\sigma^2$, is excited from the vacuum fluctuations. The excited modes of $\sigma$ amplify the super-Hubble isocurvature perturbations, which seed the second order curvature perturbations to give rise to a significantly large non-Gaussianity. Our results show that within 3 inflaton oscillations for a range of parameters, $1
AB - In this paper we derive a generic expression, which is valid for scales larger than Hubble radius and contains only the local terms, for the second order curvature perturbations for more than one field, provided the expansion is sourced by the energy density of a single field. As an application, motivated by our previous paper [1], we apply our formalism to two fields during preheating, where the inflaton oscillations are sourced by $\lambda\phi^4$ potential which is governing the expansion of the Universe. A second field $\sigma$, coupled to the inflaton through $g^2\phi^2\sigma^2$, is excited from the vacuum fluctuations. The excited modes of $\sigma$ amplify the super-Hubble isocurvature perturbations, which seed the second order curvature perturbations to give rise to a significantly large non-Gaussianity. Our results show that within 3 inflaton oscillations for a range of parameters, $1
KW - cosmological perturbation theory
KW - inflation
KW - physics of the early universe
U2 - 10.1088/1475-7516/2006/04/003
DO - 10.1088/1475-7516/2006/04/003
M3 - Journal article
VL - 2006
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 4
M1 - 3
ER -