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arXiv · 1005.1219

On non-linear CMB temperature anisotropy from gravitational perturbations

Xian Gao
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Abstract

Non-linear CMB temperature anisotropies up to the third-order on large scales are calculated. On large scales and in the Sachs-Wolfe limit, we give the explicit expression for the observed temperature anisotropy in terms of the primordial curvature perturbation up to the third-order. We derived the final bispectrum and trispectrum of anisotropies and the corresponding non-linear parameters, in which the contributions to the observed non-Gaussianity from primordial perturbations and from the non-linear mapping from primordial curvature perturbation to the temperature anisotropy are transparently separated.

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Xian Gao. 2010-05-07. On non-linear CMB temperature anisotropy from gravitational perturbations. https://doi.org/10.1103/physrevd.82.103004

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