Statistical anisotropy in CMB spectral distortions

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 $0.01\lesssim k\mathrm{Mpc}\lesssim 1$. 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 $4\pi ⟨y_{2m}⟩=-6.8A_2\times 10^{-9}{Y}_{2m}(\mathbf{d})$ 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.

5 pages, 4 figures, published version

References in corpus (9)

• Cosmological Collider Physics
• Parity-violating and anisotropic correlations in pseudoscalar inflation
• Imprints of Spinning Particles on Primordial Cosmological Perturbations
• Detecting higher spin fields through statistical anisotropy in the CMB and galaxy power spectra
• Evolution of CMB spectral distortion anisotropies and tests of primordial non-Gaussianity
• Polypolar spherical harmonic decomposition of galaxy correlators in redshift space: Toward testing cosmic rotational symmetry
• Angular dependence of primordial trispectra and CMB spectral distortions
• General quadrupolar statistical anisotropy: Planck limits
• Reconstruction of a direction-dependent primordial power spectrum from Planck CMB data

Cited by in corpus (2)

• The synergy between CMB spectral distortions and anisotropies
• Gravitational Matter Creation, Multi-fluid Cosmology and Kinetic Theory