Non-gaussianity at tree and one-loop levels from vector field perturbations
Abstract
We study the spectrum P_\zeta and bispectrum B_\zeta of the primordial curvature perturbation \zeta when 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_\zeta and (or) in B_\zeta) 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_\zeta. 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.
Keywords
Cite
@article{arxiv.0909.4064,
title = {Non-gaussianity at tree and one-loop levels from vector field perturbations},
author = {Cesar A. Valenzuela-Toledo and Yeinzon Rodriguez and David H. Lyth},
journal= {arXiv preprint arXiv:0909.4064},
year = {2009}
}
Comments
LaTeX file, 11 pages, Main body: 8 pages, References: 3 pages. v2: Minor corrections. References added. Conclusions unchanged. v3: Minor corrections. Some references added and others updated. Version accepted for publication in Physical Review D