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arXiv · 1603.02243

On CMB B-Mode Non-Gaussianity

P. Daniel Meerburg·Joel Meyers·Alex van Engelen·Yacine Ali-Haïmoud
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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 non-vanishing and is of the same order in slow-roll parameters as the scalar-scalar-scalar bispectrum. We calculate the $\langle BTT\rangle$ 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.

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P. Daniel Meerburg, Joel Meyers, Alex van Engelen, Yacine Ali-Haïmoud. 2016-03-07. On CMB B-Mode Non-Gaussianity. https://doi.org/10.1103/physrevd.93.123511

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