The bispectrum of galaxies from high-redshift galaxy surveys: primordial non-Gaussianity and non-linear galaxy bias - AstrophysicsReport as inadecuate




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Abstract: The greatest challenge in the interpretation of galaxy clustering data fromany surveys is galaxy bias. Using a simple Fisher matrix analysis, we show thatthe bispectrum provides an excellent determination of linear and non-linearbias parameters of intermediate and high-z galaxies, when all measurabletriangle configurations down to mildly non-linear scales, where perturbationtheory is still valid, are included. The bispectrum is also a powerful probe ofprimordial non-Gaussianity. The planned galaxy surveys at z>2 should yieldconstraints on non-Gaussian parameters, f {NL}^{loc.} and f {NL}^{eq.}, thatare comparable to, or even better than, those from CMB experiments. We studyhow these constraints improve with volume, redshift range, as well as thenumber density of galaxies. Finally, we show that a halo occupationdistribution may be used to improve these constraints further by liftingdegeneracies between gravity, bias, and primordial non-Gaussianity.



Author: Emiliano Sefusatti, Eiichiro Komatsu

Source: https://arxiv.org/







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