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arXiv · 1902.01142

CMB-S4 forecast on the primordial non-Gaussianity parameter of feature models

Wuhyun Sohn·James Fergusson
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Abstract

We present forecasts on the primordial non-Gaussianity parameter $f_\text{NL}$ of feature models for the future Cosmic Microwave Background Stage-4 (CMB-S4) experiments. The Fisher matrix of the bispectrum estimator was computed using noise covariances expected for preliminary CMB-S4 specifications including ones for the Simons Observatory. We introduce a novel method that improves the computation by orthonormalising the covariance matrix. The most sensitive CMB-S4 experiment with 1' beam and 1$μK$-arcmin noise would yield a factor of 1.7-2.2 times more stringent constraints compared to Planck. Under the Simons Observatory baseline conditions the improvement would be about 1.3-1.6 times to Planck. We also thoroughly studied the effects of various model and experimental parameters on the forecast. Detailed analysis on the constraints coming from temperature and E-mode polarisation, in particular, provided some insight into detecting oscillatory features in the CMB bispectrum.

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Wuhyun Sohn, James Fergusson. 2019-08-30. CMB-S4 forecast on the primordial non-Gaussianity parameter of feature models. https://doi.org/10.1103/physrevd.100.063536

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