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arXiv · 0905.4732

CMB lensing and primordial non-Gaussianity

Duncan Hanson·Kendrick M. Smith·Anthony Challinor·Michele Liguori
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Abstract

We study the effects of gravitational lensing on the estimation of non-Gaussianity from the bispectrum of the cosmic microwave background (CMB) temperature anisotropies. We find that the effect of lensing on the bispectrum may qualitatively be described as a smoothing of the acoustic features analogous to the temperature power spectrum. In contrast to previous results, for a Planck-like experiment which is cosmic-variance limited to L=2000, we find that lensing causes no significant degradation of our ability to constrain the non-Gaussianity amplitude fNL for both local and equilateral configurations, provided that the biases due to the cross correlation between the lensing potential and the integrated-Sachs-Wolfe (ISW) contribution to the CMB temperature are adequately understood. With numerical simulations, we also verify that low-order Taylor approximations to the lensed bispectrum and ISW-lensing biases are accurate.

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Duncan Hanson, Kendrick M. Smith, Anthony Challinor, Michele Liguori. 2010-06-18. CMB lensing and primordial non-Gaussianity. https://doi.org/10.1103/physrevd.80.083004

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