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Non-gaussianity at tree and one-loop levels from vector field perturbations

Cesar A. Valenzuela-Toledo·Yeinzon Rodriguez·David H. Lyth
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Abstract

We study the spectrum P_ζand bispectrum B_ζof the primordial curvature perturbation ζwhen the latter is generated by scalar and vector field perturbations. The tree-level and one-loop contributions from vector field perturbations are worked out considering the possibility that the one-loop contributions may be dominant over the tree level terms (both (either) in P_ζand (or) in B_ζ) and viceversa. The level of non-gaussianity in the bispectrum, f_{NL}, is calculated and related to the level of statistical anisotropy in the power spectrum, g_ζ. For very small amounts of statistical anisotropy in the power spectrum, the level of non-gaussianity may be very high, in some cases exceeding the current observational limit.

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Cesar A. Valenzuela-Toledo, Yeinzon Rodriguez, David H. Lyth. 2009-11-11. Non-gaussianity at tree and one-loop levels from vector field perturbations. https://doi.org/10.1103/physrevd.80.103519

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