Abstract
We study the degree to which the cosmic microwave background (CMB) can be used to constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on the correlation of one polarization B mode with two temperature modes. In the simplest models of inflation, the tensor-scalar-scalar primordial bispectrum is nonvanishing and is of the same order in slow-roll parameters as the scalar-scalar-scalar bispectrumr. We calculate the {BTT} correlation arising from a primordial tensor-scalar-scalar bispectrum, and show that constraints from an experiment like CMB-Stage IV using this observable are more than an order of magnitude better than those on the same primordial coupling obtained from temperature measurements alone. We argue that B-mode non-Gaussianity opens up an as-yet-unexplored window into the early Universe, demonstrating that significant information on primordial physics remains to be harvested from CMB anisotropies.
Original language | English (US) |
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Article number | 123511 |
Journal | Physical Review D |
Volume | 93 |
Issue number | 12 |
DOIs | |
State | Published - Jun 7 2016 |
Externally published | Yes |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)