Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys

Fuente: arXiv
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Auteurs principaux: Jolicoeur, Sheean, Maartens, Roy, Dlamini, Simthembile
Format: Preprint
Publié: 2023
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author Jolicoeur, Sheean
Maartens, Roy
Dlamini, Simthembile
author_facet Jolicoeur, Sheean
Maartens, Roy
Dlamini, Simthembile
contents Surveys of the matter distribution contain `fossil' information on possible non-Gaussianity that is generated in the primordial Universe. This primordial signal survives only on the largest scales where cosmic variance is strongest. By combining different surveys in a multi-tracer approach, we can suppress the cosmic variance and significantly improve the precision on the level of primordial non-Gaussianity. We consider a combination of an optical galaxy survey, like the recently initiated DESI survey, together with a new and very different type of survey, a 21 cm intensity mapping survey, like the upcoming SKAO survey. A Fisher forecast of the precision on the local primordial non-Gaussianity parameter $f_{\mathrm{NL}}$, shows that this multi-tracer combination, together with non-overlap single-tracer information, can deliver precision comparable to that from the CMB. Taking account of the largest systematic, i.e. foreground contamination in intensity mapping, we find that $σ(f_{\mathrm{NL}}) \sim 4$.
format Preprint
id arxiv_https___arxiv_org_abs_2301_02406
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
Jolicoeur, Sheean
Maartens, Roy
Dlamini, Simthembile
Cosmology and Nongalactic Astrophysics
Surveys of the matter distribution contain `fossil' information on possible non-Gaussianity that is generated in the primordial Universe. This primordial signal survives only on the largest scales where cosmic variance is strongest. By combining different surveys in a multi-tracer approach, we can suppress the cosmic variance and significantly improve the precision on the level of primordial non-Gaussianity. We consider a combination of an optical galaxy survey, like the recently initiated DESI survey, together with a new and very different type of survey, a 21 cm intensity mapping survey, like the upcoming SKAO survey. A Fisher forecast of the precision on the local primordial non-Gaussianity parameter $f_{\mathrm{NL}}$, shows that this multi-tracer combination, together with non-overlap single-tracer information, can deliver precision comparable to that from the CMB. Taking account of the largest systematic, i.e. foreground contamination in intensity mapping, we find that $σ(f_{\mathrm{NL}}) \sim 4$.
title Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2301.02406