Local stochastic non-Gaussianity and N-body simulations

Journal Article · Tue Nov 01 04:00:00 EDT 2011 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2011/11/009· OSTI ID:22280251

Smith, Kendrick M. ^[1]; LoVerde, Marilena ^[2]

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1. Princeton University Observatory, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)
2. Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

Large-scale clustering of highly biased tracers of large-scale structure has emerged as one of the best observational probes of primordial non-Gaussianity of the local type (i.e. f{sub NL}{sup local}). This type of non-Gaussianity can be generated in multifield models of inflation such as the curvaton model. Recently, Tseliakhovich, Hirata, and Slosar showed that the clustering statistics depend qualitatively on the ratio of inflaton to curvaton power ξ after reheating, a free parameter of the model. If ξ is significantly different from zero, so that the inflaton makes a non-negligible contribution to the primordial adiabatic curvature, then the peak-background split ansatz predicts that the halo bias will be stochastic on large scales. In this paper, we test this prediction in N-body simulations. We find that large-scale stochasticity is generated, in qualitative agreement with the prediction, but that the level of stochasticity is overpredicted by ≈ 30%. Other predictions, such as ξ independence of the halo bias, are confirmed by the simulations. Surprisingly, even in the Gaussian case we do not find that halo model predictions for stochasticity agree consistently with simulations, suggesting that semi-analytic modeling of stochasticity is generally more difficult than modeling halo bias.

• OSTI ID: 22280251
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 11 Vol. 2011; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPUTERIZED SIMULATION
COSMOLOGY
INFLATIONARY UNIVERSE
INFLATONS
PROBES
STOCHASTIC PROCESSES