arXiv Analytics

Sign in

arXiv:1906.04730 [astro-ph.CO]AbstractReferencesReviewsResources

Constraining primordial non-Gaussianity using two galaxy surveys and CMB lensing

Mario Ballardini, William Luke Matthewson, Roy Maartens

Published 2019-06-11Version 1

Next-generation galaxy surveys will be able to measure perturbations on scales beyond the equality scale. On these ultra-large scales, primordial non-Gaussianity leaves signatures that can shed light on the mechanism by which perturbations in the early Universe are generated. We perform a forecast analysis for constraining local type non-Gaussianity and its two-parameter extension with a simple scale-dependence. We combine different future galaxy surveys -- a 21cm intensity mapping survey and two photometric galaxy surveys -- via the multi-tracer approach. Furthermore we then include CMB lensing from a CMB Stage 4 experiment in the multi-tracer, which can improve the constraints on bias parameters. We forecast $\sigma(f_{\rm NL}) \simeq 0.9$ (1.4) by combining SKA1, a Euclid-like (LSST-like) survey, and CMB-S4 lensing. With CMB lensing, the precision on $f_{\rm NL}$ improves by up to a factor of 2, showing that a joint analysis is important. In the case with running of $f_{\rm NL}$, our results show that the combination of upcoming cosmological surveys could achieve $\sigma(n_{\rm NL}) \simeq 0.12$ (0.22) on the running index.

Related articles: Most relevant | Search more
arXiv:1607.01761 [astro-ph.CO] (Published 2016-07-06)
Looking through the same lens: shear calibration for LSST, Euclid & WFIRST with stage 4 CMB lensing
arXiv:1801.09280 [astro-ph.CO] (Published 2018-01-28)
Constraining Primordial non-Gaussianity with Bispectrum and Power Spectum from Upcoming Optical and Radio Surveys
arXiv:1011.4510 [astro-ph.CO] (Published 2010-11-19, updated 2010-11-29)
CMB Lensing - Power Without Bias