The Effect of Local non-Gaussianity on the Matter Bispectrum at Small Scales
May, 2012
34 pages
Published in:
- JCAP 08 (2012) 036
e-Print:
- 1205.2015 [astro-ph.CO]
Report number:
- HIP-2012-11-TH
View in:
Citations per year
Abstract: (arXiv)
We compute the matter bispectrum in the presence of primordial local non-Gaussianity over a wide range of scales, including the very small nonlinear ones. We use the Halo Model approach, considering non-Gaussian corrections to the halo profiles, the halo mass function and the bias functions. We compare our results in the linear and mildly nonlinear scales to a large ensemble of Gaussian and non-Gaussian numerical simulations. We consider both squeezed and equilateral configurations, at redshift z = 0 and z = 1. For z = 0, the deviations between the Halo Model and the simulations are smaller than 10% in the squeezed limit, both in the Gaussian and non-Gaussian cases. The Halo Model allows to make predictions on scales much smaller than those reached by numerical simulations. For local non-Gaussian initial conditions with a parameter fNL = 100, we find an enhancement of the bispectrum in the squeezed configuration k = k3 = k2 >> k1 \sim 0.01 h^{-1} Mpc, of \sim 15% and \sim 25% on scales k \sim 1 h^{-1} Mpc, at z = 0 and z = 1 respectively. This is mainly due to the non-Gaussian corrections in the linear bias. Finally we provide a very simple expression valid for any scenario, i.e. for any choice of the halo profile, mass and bias functions, which allow for a fast evaluation of the bispectrum on squeezed configurations.Note:
- 34 pages, 10 figures, Submitted to JCAP
- halo: model
- halo: mass
- effect: local
- non-Gaussianity: primordial
- bispectrum
- numerical calculations
- nonlinear
- boundary condition
- enhancement
- redshift
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Figures(10)
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