Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-30859
Lam, T Y; Sheth, R K; Desjacques, V (2009). The initial shear field in models with primordial local non-Gaussianity and implications for halo and void abundances. Monthly Notices of the Royal Astronomical Society, 399(3):1482-1494.
PDF (Accepted manuscript, Version 2)
PDF (Accepted manuscript, Version 1)
We generalize the Doroshkevich's celebrated formulae for the eigenvalues of the initial shear field associated with Gaussian statistics to the local non-Gaussian fnl model. This is possible because, to at least second order in fnl , distributions at fixed overdensity are unchanged from the case fnl= 0 . We use this generalization to estimate the effect of fnl≠ 0 on the abundance of virialized haloes. Halo abundances are expected to be related to the probability that a certain quantity in the initial fluctuation field exceeds a threshold value, and we study two choices for this variable: it can either be the sum of the eigenvalues of the initial deformation tensor (the initial overdensity) or its smallest eigenvalue. The approach based on a critical overdensity yields results which are in excellent agreement with numerical measurements. We then use these same methods to develop approximations describing the sensitivity of void abundances on fnl . While a positive fnl produces more extremely massive haloes, it makes fewer extremely large voids. Its effect thus is qualitatively different from a simple rescaling of the normalization of the density fluctuation field σ8. Therefore, void abundances furnish complementary information to cluster abundances, and a joint comparison of both might provide interesting constraints on primordial non-Gaussianity.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Theoretical Physics|
|Uncontrolled Keywords:||methods: analytical; large-scale structure of Universe|
|Deposited On:||26 Feb 2010 16:00|
|Last Modified:||23 Nov 2012 14:20|
|Funders:||Swiss National Foundation [200021-116696/1]|
|Additional Information:||The attached file is a preprint (accepted version) of an article published in Monthly Notices of the Royal Astronomical Society. The definitive version is available at www3.interscience.wiley.com|
|WoS Citation Count:||13|
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