Statistical anisotropy in CMB spectral distortions

Atsuhisa Ota

doi:10.1016/j.physletb.2019.01.030

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arXiv · 1810.03928

Statistical anisotropy in CMB spectral distortions

Atsuhisa Ota

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Abstract

Measurements of the cosmic microwave background (CMB) spectral $y$-distortion anisotropy offer a test for the statistical isotropy of the primordial density perturbations on $0.01\lesssim k{\rm Mpc}\lesssim 1$. We compute the 1-point ensemble averages of the $y$-distortion anisotropies which vanish for the statistically isotropic perturbations. For the quadrupole statistical anisotropy, we find $4π\langle y_{2m}\rangle=-6.8A_2\times 10^{-9}Y_{2m}(\mathbf d )$ with the quadruple Legendre coefficient of the anisotropic powerspectrum $A_2$ and the $\ell=2$ spherical harmonics $Y_{2m}(\mathbf d )$ for the preferred direction $\mathbf d $. Also, we discuss the cosmic variance of the $y$-distortion anisotropy in the statistically anisotropic Universe.

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Atsuhisa Ota. 2019-01-25. Statistical anisotropy in CMB spectral distortions. https://doi.org/10.1016/j.physletb.2019.01.030

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