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Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
- Source :
- EPJC 83 (2023) 320
- Publication Year :
- 2023
-
Abstract
- 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 $\sigma(f_{\mathrm{NL}}) \sim 4$.<br />Comment: 10+5 pages, 4 figures, "Minor corrections, main results unchanged. Version accepted by EPJC"
- Subjects :
- Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- Database :
- arXiv
- Journal :
- EPJC 83 (2023) 320
- Publication Type :
- Report
- Accession number :
- edsarx.2301.02406
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1140/epjc/s10052-023-11482-2