Parity violation in the CMB bispectrum by a rolling pseudoscalar
- Dipartimento di Fisica e Astronomia ''G. Galilei'', Università degli Studi di Padova, via Marzolo 8, I-35131, Padova (Italy)
- Department of Physics and Astrophysics, Nagoya University, Nagoya, Aichi, 464-8602 (Japan)
We investigate parity-violating signatures of temperature and polarization bispectra of the cosmic microwave background (CMB) in an inflationary model where a rolling pseudoscalar produces large equilateral tensor non-Gaussianity. By a concrete computation based on full-sky formalism, it is shown that resultant CMB bispectra have nonzero signals in both parity-even (ℓ{sub 1}+ℓ{sub 2}+ℓ{sub 3} = even) and parity-odd (ℓ{sub 1}+ℓ{sub 2}+ℓ{sub 3} = odd) spaces, and are almost uncorrelated with usual scalar-mode equilateral bispectra. These characteristic signatures and polarization information help to detect such tensor non-Gaussianity. Use of both temperature and E-mode bispectra potentially improves of 400% the detectability with respect to an analysis with temperature bispectrum alone. Considering B-mode bispectrum, the signal-to-noise ratio may be able to increase by 3 orders of magnitude. We present the 1σ uncertainties of a parameter depending on a coupling constant and a rolling condition for the pseudoscalar expected in the Planck and the proposed PRISM experiments.
- OSTI ID:
- 22369909
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2013, Issue 11; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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