CMB hemispherical asymmetry: long mode modulation and non-Gaussianity

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Published 1 August 2014 © 2014 IOP Publishing Ltd and Sissa Medialab srl
, , Citation Mohammad Hossein Namjoo et al JCAP08(2014)002 DOI 10.1088/1475-7516/2014/08/002

1475-7516/2014/08/002

Abstract

The observed hemispherical asymmetry in CMB map can be explained by modulation from a long wavelength super horizon mode which non-linearly couples to the CMB modes. We address the criticism in [1] about the role of non-Gaussianities in squeezed and equilateral configurations in generating hemispherical asymmetry from the long mode modulation. We stress that the modulation is sensitive to the non-Gaussianity in the squeezed limit. In addition, we demonstrate the validity of our approach in providing a consistency condition relating the amplitude of dipole asymmetry to fNL in the squeezed limit.

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