2015/07/21 by Alvise Raccanelli, Raccanelli, Alvise, Maresuke Shiraishi +13
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Geophysics and Gravity Measurements #Radio Astronomy Observations and Technology #Statistical and numerical algorithms
paper · pdf · doi:10.48550/arxiv.1507.05903
openalex publication_date 2015/07/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate how well future large-scale radio surveys could measure\ndifferent shapes of primordial non-Gaussianity; in particular we focus on\nangle-dependent non-Gaussianity arising from primordial anisotropic sources,\nwhose bispectrum has an angle dependence between the three wavevectors that is\ncharacterized by Legendre polynomials \PL and expansion\ncoefficients cL. We provide forecasts for measurements of galaxy power\nspectrum, finding that Large-Scale Structure (LSS) data could allow\nmeasurements of primordial non-Gaussianity competitive or improving upon\ncurrent constraints set by CMB experiments, for all the shapes considered. We\nargue that the best constraints will come from the possibility to assign\nredshift information to radio galaxy surveys, and investigate a few possible\nscenarios for the EMU and SKA surveys. A realistic (futuristic) modeling could\nprovide constraints of f rm NL rm loc \≈ 1 (0.5) for the local\nshape, f rm NL of \O(10) (\O(1)) for the orthogonal,\nequilateral and folded shapes, and cL=1 \≈ 80 (2), cL=2 \≈\n400 (10) for angle-dependent non-Gaussianity. The more futuristic forecasts\nshow the potential of LSS analyses to considerably improve current constraints\non non-Gaussianity, and so on models of the primordial Universe. Finally, we\nfind the minimum requirements that would be needed to reach\n\σ(cL=1)=10, which can be considered as a typical (lower) value\npredicted by some (inflationary) models.\n