TY - JOUR
T1 - Non-Gaussianity from isocurvature perturbations
T2 - Analysis of trispectrum
AU - Kawakami, Etsuko
AU - Kawasaki, Masahiro
AU - Nakayama, Kazunori
AU - Takahashi, Fuminobu
PY - 2009
Y1 - 2009
N2 - Non-Gaussianity may exist in the CDM isocurvature perturbation. We provide general expressions for the bispectrum and trispectrum of both adiabatic and isocurvature pertubations. We apply our result to the QCD axion case, and found a consistency relation between the coefficients of the bispectrum and trispectrum: τ NL (iso) 10 3[f NL (iso)] 4/3, if the axion is dominantly produced by quantum fluctuation. Thus future observations of the trispectrum, as well as the bispectrum, will be important for understanding the origin of the CDM and baryon asymmetry.
AB - Non-Gaussianity may exist in the CDM isocurvature perturbation. We provide general expressions for the bispectrum and trispectrum of both adiabatic and isocurvature pertubations. We apply our result to the QCD axion case, and found a consistency relation between the coefficients of the bispectrum and trispectrum: τ NL (iso) 10 3[f NL (iso)] 4/3, if the axion is dominantly produced by quantum fluctuation. Thus future observations of the trispectrum, as well as the bispectrum, will be important for understanding the origin of the CDM and baryon asymmetry.
KW - Axions
KW - Cosmological perturbation theory
KW - Cosmology of theories beyond the SM
KW - Physics of the early universe
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U2 - 10.1088/1475-7516/2009/09/002
DO - 10.1088/1475-7516/2009/09/002
M3 - Article
AN - SCOPUS:70350700682
SN - 1475-7516
VL - 2009
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 9
M1 - 002
ER -