The non-linear probability distribution function in models with local primordial non-Gaussianity

Lam, Tsz Yan; Sheth, Ravi K.

doi:10.1111/j.1365-2966.2009.14672.x

Cited by 16 publications

(26 citation statements)

References 38 publications

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“…However, cosmic microwave background (CMB) temperature fluctuations, at high‐order perturbation theory (see e.g. Zaldarriaga 2000; Bartolo et al 2004, 2010; Seery & Lidsey 2005; Assadullahi, Väliviita & Wands 2007; Beltrán 2008; Cooray, Sarkar & Serra 2008; Liguori & Riotto 2008; Khatri & Wandelt 2009; Lam & Sheth 2009; Gao 2010; Pitrou, Uzan & Bernardeau 2010; Yadav & Wandelt 2010), could have deviations from the purely Gaussian shape and leave room for non‐Gaussian models. Additional studies of the excursion set formalism and analyses of N ‐body numerical simulations of large‐scale structures have shown how the abundance of rare‐peak dark matter haloes and their clustering properties and distribution might be affected (e.g.…”

Section: Introductionmentioning

confidence: 99%

Baryon history and cosmic star formation in non-Gaussian cosmological models: numerical simulations

Maio

Iannuzzi

2011

Monthly Notices of the Royal Astronomical Society

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We present the first numerical, N‐body, hydrodynamical, chemical simulations of cosmic structure formation in the framework of non‐Gaussian models. We study the impact of primordial non‐Gaussianities on early chemistry (e−, H, H+, H−, He, He+, He++, H2, H+2, D, D+, HD, HeH+), molecular and atomic gas cooling, star formation, metal (C, O, Si, Fe, Mg, S) enrichment, Population III (popIII) and Population II–I (popII) transition and on the evolution of ‘visible’ objects. We find that non‐Gaussianities can have some consequences on baryonic structure formation at very early epochs, but the subsequent evolution at later times washes out any difference among the various models. When assuming reasonable values for primordial non‐Gaussian perturbations, it turns out that they are responsible for (i) altering early molecular fractions in the cold, dense gas phase by ∼10 per cent; (ii) inducing small temperature fluctuations of ≲10 per cent during the cosmic evolution of primordial objects; (iii) influencing the onset of the first star formation events, at z > 15, and of the popIII/popII transition by up to some 107 yr; (iv) determining variations of ≲10 per cent in the gas cloud and stellar mass distributions after the formation of the first structures; and (v) causing only mild variations in the chemical history of the Universe. We stress, though, that purely non‐Gaussian effects might be difficult to address, since they are strictly intertwined with additional physical phenomena (e.g. primordial gas bulk flows, unknown primordial popIII stellar mass function etc.) that have a similar or stronger impact on the behaviour of the baryons.

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Section: Introductionmentioning

confidence: 99%

Baryon history and cosmic star formation in non-Gaussian cosmological models: numerical simulations

Maio

Iannuzzi

2011

Monthly Notices of the Royal Astronomical Society

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“…Buchbinder, Khoury & Ovrut 2008; Khoury & Piazza 2009; Silvestri & Trodden 2008, and references therein). Constraints on this model tend to be of two types – from the CMB (Hikage et al 2008; McEwen et al 2008; Yadav & Wandelt 2008; Komatsu et al 2009; Rossi et al 2009) and from large‐scale structures in the Universe (Koyama, Soda & Taruya 1999; Matarrese, Verde & Jimenez 2000; Scoccimarro, Sefusatti & Zaldarriaga 2004; Izumi & Soda 2007; Sefusatti & Komatsu 2007; Afshordi & Tolley 2008; Carbone, Verde & Matarrese 2008; Dalal et al 2008; Desjacques, Seljak & Iliev 2009; Grossi et al 2008; Lo Verde et al 2008; Matarrese & Verde 2008; McDonald 2008; Pillepich, Porciani & Hahn 2008; Slosar et al 2008; Taruya, Koyama & Matsubara 2008; Grossi et al 2009; Kamionkowski, Verde & Jimenez 2009; Lam & Sheth 2009b; Slosar 2009).…”

Section: Introductionmentioning

confidence: 99%

The initial shear field in models with primordial local non-Gaussianity and implications for halo and void abundances

Lam¹,

Sheth²,

Desjacques³

2009

Monthly Notices of the Royal Astronomical Society

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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.

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“…[5][6][7][8][9][10] and was validated by large-scale cosmological simulations with non-Gaussian initial conditions [7,[11][12][13]. More recently NG effects on the large scale clustering of collapsed haloes were studied * Electronic address: suetyinm@usc.edu † Electronic address: pierpaol@usc.edu by [12,[14][15][16]. They found that the linear biasing parameter acquires a scale dependence, which modifies the power spectrum of the the distribution of cosmic structures most prominently at large scales.…”

Section: Introductionmentioning

confidence: 99%

Constraints on non-Gaussianity from Sunyaev-Zeldovich cluster surveys

Mak

Pierpaoli

2012

Phys. Rev. D

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We perform a Fisher matrix analysis to forecast the capability of ongoing and future SunyaevZeldovich cluster surveys in constraining the deviations from Gaussian distribution of primordial density perturbations. We use the constraining power of the cluster number counts and clustering properties to forecast limits on the fNL parameter. The primordial non-Gaussianity effects on the mass function and halo bias are considered. We adopt self-calibration for the mass-observable scaling relation, and evaluate constraints for the SPT, Planck, CCAT-like, SPTPol and ACTPol surveys. We show that the scale-dependence of halo bias induced by the local NG provides strong constraints on fNL, while the results from number count are two orders of magnitude worse. When combining information from number counts and power spectrum, the Planck cluster catalog provides the tightest constraint with σ f NL = 7 (68% C.L.) even for relatively conservative assumptions on the expected cluster yields and systematics. This value is a factor of 2 smaller than the 1σ error as measured by WMAP CMB measurements, and comparable to what expected from Planck. We find that the results are mildly sensitive to the mass threshold of the surveys, but strongly depend on the survey coverage: a full-sky survey like Planck is more favorable because it can probe longer wavelengths modes which are most sensitive to NG effects. In addition, the constraints are largely insensitive to priors on nuisance parameters as they are mainly driven by the power spectrum probe which has a mild dependence on the mass-observable relations.

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The non-linear probability distribution function in models with local primordial non-Gaussianity

Cited by 16 publications

References 38 publications

Baryon history and cosmic star formation in non-Gaussian cosmological models: numerical simulations

Baryon history and cosmic star formation in non-Gaussian cosmological models: numerical simulations

The initial shear field in models with primordial local non-Gaussianity and implications for halo and void abundances

Constraints on non-Gaussianity from Sunyaev-Zeldovich cluster surveys

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