Signatures of Non-Gaussianity in the Curvaton Model
Abstract
We discuss the signatures of non-Gaussianity in the curvaton model where the potential includes also a non-quadratic term. In such a case the non-linearity parameter f_NL can become very small, and we show that non-Gaussianity is then encoded in the non-reducible non-linearity parameter g_NL of the trispectrum, which can be very large. Thus the place to look for the non-Gaussianity in the curvaton model may be the trispectrum rather than the bispectrum. We also show that g_NL measures directly the deviation of the curvaton potential from the purely quadratic form. While g_NL depends on the strength of the non-quadratic terms relative to the quadratic one, we find that for reasonable cases roughly g_NL\sim O(-10^4)-O(-10^5), which are values that may well be accessible by future observations.
Keywords
Cite
@article{arxiv.0807.3069,
title = {Signatures of Non-Gaussianity in the Curvaton Model},
author = {Kari Enqvist and Tomo Takahashi},
journal= {arXiv preprint arXiv:0807.3069},
year = {2011}
}
Comments
10 pages, 4 figures