Signatures of non-Gaussianity in the curvaton model

Journal Article · Mon Sep 15 04:00:00 EDT 2008 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2008/09/012· OSTI ID:22156742

Enqvist, Kari ^[1]; Takahashi, Tomo ^[2]

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1. Helsinki Institute of Physics, University of Helsinki, PO Box 64, FIN-00014 (Finland)
2. Department of Physics, Saga University, Saga 840-8502 (Japan)

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{sub NL} can become very small, and we show that non-Gaussianity is then encoded in the non-reducible non-linearity parameter g{sub 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{sub NL} measures directly the deviation of the curvaton potential from the purely quadratic form. While g{sub NL} depends on the strength of the non-quadratic terms relative to the quadratic one, we find that for reasonable cases roughly g{sub NL}{approx}O(-10{sup 4})-O(-10{sup 5}), which are values that may well be accessible by future observations.

• OSTI ID: 22156742
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 09 Vol. 2008; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMOLOGICAL MODELS
MINKOWSKI SPACE
POTENTIALS