2013/08/31 by Maresuke Shiraishi, Angelo Ricciardone, Shohei Saga · 2 citations
Mathematics · Physics and Astronomy · #Bispectrum #Computation #Cosmic microwave background #Cosmology and Gravitation Theories #Equilateral triangle #Galaxies: Formation, Evolution, Phenomena #Non-Gaussianity #Parity (physics) #Polarization (electrochemistry) #Pseudoscalar #Tensor decomposition and applications #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2013/11/051
published as JCAP11(2013)051 · 19 pages, 5 figures. Accepted for publication in JCAP
arxiv created 2013/11/21 · openalex publication_date 2013/11/21 · arxiv updated 2013/11/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/08
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 1 +ℓ 2 +ℓ 3 = even) and parity-odd (ℓ 1 +ℓ 2 +ℓ 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.