Measuring the small primordial nonGaussianity (PNG) predicted by cosmic inflation theories may help diagnose them. The detectability of PNG by its imprint on the 21cm power spectrum from the epoch of reionization is reassessed here in terms of fNL, the local nonlinearity parameter. We find that an optimum, multi-frequency observation by SKA can achieve ΔfNL∼3 (comparable to recent Planck CMB limits), while a cosmic-variance-limited array of this size like Omniscope can even detect ΔfNL∼0.2. This substantially revises the methods and results of previous work.
@article{arxiv.1305.0313,
title = {Primordial Non-Gaussianity Estimation using 21 cm Tomography from the Epoch of Reionization},
author = {Yi Mao and Anson D'Aloisio and Jun Zhang and Paul R. Shapiro},
journal= {arXiv preprint arXiv:1305.0313},
year = {2015}
}
Comments
Accepted by PRD with minor changes. References added and updated