The mass density field in simulated non-Gaussian scenarios

Grossi, M.; Branchini, E.; Dolag, K.; Matarrese, S.; Moscardini, L.

doi:10.1111/j.1365-2966.2008.13783.x

Cited by 50 publications

(82 citation statements)

References 47 publications

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“…This condition guarantees that the statistical properties of the cosmological density field are modeled accurately throughout the range of scales spanned by the simulation. In particular, this is fundamental for probing the imprints of primordial non-Gaussianities on large-scale structure, a topic of current interest (e.g., Dalal et al 2008;Grossi et al 2008;Hikage et al 2008). These results have two implications.…”

Section: Discussionmentioning

confidence: 99%

Discreteness Effects in ΛCDM Simulations: A Wavelet‐Statistical View

Romeo

Agertz

Moore

et al. 2008

Astrophysical Journal

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The effects of particle discreteness in N-body ÃCDM simulations are still an intensively debated issue. In this paper we explore such effects, taking into account the scatter caused by the randomness of the initial conditions and focusing on the statistical properties of the cosmological density field. For this purpose, we run large sets of ÃCDM simulations and analyze them using a wide variety of diagnostics, including new and powerful wavelet statistics. Among other facts, we point out (1) that dynamical evolution does not propagate discreteness noise up from the small scales at which it is introduced and (2) that one should aim to satisfy the condition $ 2d, where is the force resolution and d is the interparticle distance. We clarify what such a condition means and how to implement it in modern cosmological codes. Subject headingg s: cosmology: miscellaneous -dark matter -large-scale structure of universemethods: n-body simulations -methods: numerical -methods: statistical

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Section: Discussionmentioning

confidence: 99%

Discreteness Effects in ΛCDM Simulations: A Wavelet‐Statistical View

Romeo

Agertz

Moore

et al. 2008

Astrophysical Journal

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“…The quadratic coupling f NL 2 also affect the matter power spectrum at leading order [38,84], positive values of f NL increasing the small scale power. However, the relative size of this k-dependent correction, m ðk; f NL Þ, is at a per cent level only in the weakly nonlinear regime k & 0:1h Mpc À1 [53,85] and fades rapidly as one goes to larger scales.…”

Section: B Biasmentioning

confidence: 99%

Signature of primordial non-Gaussianity ofϕ3type in the mass function and bias of dark matter haloes

2010

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We explore the effect of a cubic correction g NL 3 on the mass function and bias of dark matter haloes extracted from a series of large N-body simulations and compare it to theoretical predictions. Such cubic terms can be motivated in scenarios like the curvaton model, in which a large cubic correction can be produced while simultaneously keeping the quadratic f NL 2 correction small. The deviation from the Gaussian halo mass function is in reasonable agreement with the theoretical predictions. The scaledependent bias correction Áb ðk; g NL Þ measured from the auto-and cross-power spectrum of haloes, is similar to the correction in f NL models, but the amplitude is lower than theoretical expectations. Using the compilation of LSS data in [A. Slosar et al., J. Cosmol. Astropart. Phys. 08 (2008) 031], we obtain for the first time a limit on g NL of À3:5 Â 10 5 < g NL < þ8:2 Â 10 5 (at 95% CL). This limit will improve with the future LSS data by 1-2 orders of magnitude, which should test many of the scenarios of this type.

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“…Another recent result has shown that the nonlinear dark matter power spectrum alone is sensitive to the presence of f NL [16,17,19,21,30]. This prompted [31] to propose that the statistics of the initial conditions could be tested through weak gravitational lensing by large-scale structure, in particular through measurement of the twopoint shear correlation functions.…”

Section: Introductionmentioning

confidence: 99%

Publisher’s Note: Nonlinear clustering in models with primordial non-Gaussianity: The halo model approach [Phys. Rev. D83, 043526 (2011)]

Smith¹,

Desjacques²,

Marian³

2011

Phys. Rev. D

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We develop the halo model of large-scale structure as an accurate tool for probing primordial non-Gaussianity (PNG). In this study we focus on understanding the matter clustering at several redshifts in the context of PNG that is a quadratic correction to the local Gaussian potential, characterized by the parameter fNL. In our formulation of the halo model we pay special attention to the effect of halo exclusion, and show that this can potentially solve the long standing problem of excess power on large scales in this model. The halo model depends on the mass function, clustering of halo centers and the density profiles. We test these ingredients using a large ensemble of highresolution Gaussian and non-Gaussian numerical simulations, covering fNL = {0, +100, −100}. In particular, we provide a first exploration of how halo density profiles change in the presence of PNG. We find that for fNL positive/negative high mass haloes have an increased/decreased core density, so being more/less concentrated than in the Gaussian case. We also examine the halo bias and show that, if the halo model is correct, then there is a small asymmetry in the scale-dependence of the bias on very large scales, which arises because the Gaussian bias must be renormalized. We show that the matter power spectrum is modified by ∼ 2.5% and ∼ 3.5% on scales k ∼ 1.0 h Mpc −1 at z = 0.0 and z = 1.0, respectively. Our halo model calculation reproduces the absolute amplitude to within 10% and the ratio of non-Gaussian to Gaussian spectra to within 1%. We also measure the matter correlation function and find similarly good levels of agreement between the halo model and the data. We anticipate that this modeling will be useful for constraining fNL from measurements of the shear correlation function in future weak lensing surveys such as Euclid.

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The mass density field in simulated non-Gaussian scenarios

Cited by 50 publications

References 47 publications

Discreteness Effects in ΛCDM Simulations: A Wavelet‐Statistical View

Discreteness Effects in ΛCDM Simulations: A Wavelet‐Statistical View

Signature of primordial non-Gaussianity ofϕ3type in the mass function and bias of dark matter haloes

Publisher’s Note: Nonlinear clustering in models with primordial non-Gaussianity: The halo model approach [Phys. Rev. D83, 043526 (2011)]

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