Anisotropic CMB distortions from non-Gaussian isocurvature perturbations
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)
- University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, Helsinki 00014 (Finland)
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)
- Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501 (Japan)
We calculate the CMB μ-distortion, (μ), and the angular power spectrum of its cross-correlation with the temperature anisotropy, (μT), in the presence of the non-Gaussian neutrino isocurvature density (NID) mode. While the pure Gaussian NID perturbations give merely subdominant contributions to (μ) and do not create (μT), we show large (μT) can be realized in case where, especially, the NID perturbations S(x) are proportional to the square of a Gaussian field g(x), i.e. S(x)∝ g{sup 2}(x). Such Gaussian-squared perturbations contribute to not only the power spectrum, but also the bispectrum of CMB anisotropies. The constraints from the power spectrum is given by P{sub SS}(k{sub 0})∼P{sub g}{sup 2}(k{sub 0})∼<10{sup −10} at k{sub 0}=0.05 Mpc{sup −1}. We also forecast constraints from the CMB temperature and E-mode polarisation bispectra, and show that P{sub g}(k{sub 0})∼<10{sup −5} would be allowed from the Planck data. We find that (μ) and |l(l+1)C{sup μT}{sub l}| can respectively be as large as 10{sup −9} and 10{sup −14} with uncorrelated scale-invariant NID perturbations for P{sub g}(k{sub 0})=10{sup −5}. When the spectrum of the Gaussian field is blue-tilted (with spectral index n{sub g}≅1.5), (μT) can be enhanced by an order of magnitude.
- OSTI ID:
- 22524874
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2015, Issue 03; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
Planck 2015 results: XX. Constraints on inflation
Power spectra based Planck constraints on compensated isocurvature, and forecasts for LiteBIRD and CORE space missions