Constraints on local primordial non-Gaussianity from large scale structure

By A. Slosar, C. Hirata, Uros Seljak, Shirley Ho, Nikhil Padmanabhan. 2008

464 citations recorded by the source corpus.

Recent work has shown that the local non-Gaussianity parameter fNL induces a scale dependent bias, whose amplitude is growing with scale. Here we first rederive this result within the context of the peak–background split formalism and show that it only depends on the assumption of universality of the mass function, assuming that the halo bias only depends on the mass. We then use the extended Press–Schechter formalism to argue that this assumption may be violated and that the scale dependent bias will depend on other properties, such as the merging history of halos. In particular, in the limit of recent mergers we find that the effect is suppressed. Next we use these predictions in conjunction with a compendium of large scale data to put a limit on the value of fNL. When combining all data assuming that the halo occupation depends only on the halo mass, we get a limit of −29 (−65)<fNL<+70 (+93) at 95% (99.7%) confidence. While we use a wide range of data sets, our combined result is dominated by the signal from the SDSS photometric quasar sample. If the latter are modeled as recent mergers then the limits weaken to −31 (−96)<fNL<+70 (+96). These limits are comparable to the strongest current limits from the Wilkinson Anisotropy Probe (WMAP) five-year analysis, with no evidence of a positive signal in fNL. While the method needs to be thoroughly tested against large scale structure simulations with realistic quasar and galaxy formation models, our results indicate that this is a competitive method relative to the cosmic microwave background one and should be further pursued both observationally and theoretically.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/eb45ba1051900d7373d475d7ee3b5acab686ea36

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Citations in the corpus

Cosmology and Fundamental Physics with the Euclid Satellite (2012, methodology): “Combining current LSS data gives constraints on fNL which are comparable to the pre-Planck CMB ones (Slosar et al. 2008; Xia et al. 2010; Giannantonio et al. 2014).”
Large-scale non-Gaussian mass function and halo bias: tests on N-body simulations (2009, background): “We find that the non-Gaussian halo bias prescription of Dalal et al. (2007), Matarrese & Verde (2008), Slosar et al. (2008) and Afshordi & Tolley (2008) provides a good description of the scaling of the large-scale halo clustering of the simulations.”
The DESI Experiment Part I: Science,Targeting, and Survey Design (2016, methodology): “68 3.7 Additional Imaging Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.7.1 SDSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.7.2 PanSTARRS-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.7.3 PTF, iPTF”
Cosmological Parameters from Observations of Galaxy Clusters (2011, unknown): “Current measurements of CMB anisotropies and LSS are consistent with Gaussianity (Slosar et al. 2008; Komatsu et al. 2011).”
Large-scale bias and efficient generation of initial conditions for nonlocal primordial non-Gaussianity (2011, background): “Current constraints on such local shape are −10 < f local NL < 74 (95% limit) from the CMB bispectrum in the WMAP7 dataset [2], and −29 < f local NL < 70 (95% limit) from the scale-dependence of bias in the power spectrum of galaxies and quasars in the SDSS-II survey [9].”
Signature of supersymmetry from the early universe (2011, methodology): “This prediction motivates generalizing the LSS data analysis to include ν as a free parameter; whereas, to date, the analysis has mostly been restricted to the case ∆b ∝ k−2 [19] (but see [13, 20]).”
Primordial Non-Gaussianities from Inflation Models (2010, background): “Current constraint from large scale structure gives −29 < f local NL < 70 [172].”
The (not so) squeezed limit of the primordial 3-point function (2011, background): “Intuitively, since it probes the clustering of small halos on top of large-scale density perturbations, the halo bias is sensitive to the squeezed limit of the bispectrum [4, 5, 6], the regime studied in this paper.”
The effective field theory of multifield inflation (2010, methodology): “Therefore the resulting shape of the three-point function will have a non-vanishing squeezed limit and so it will affect the clustering statistics of collapsed objects such as galaxies and there would be constraints in studies similar to [51, 52] in addition to direct searches for a three-point func”
Primordial Non-Gaussianity and Bispectrum Measurements in the Cosmic Microwave Background and Large-Scale Structure (2010, methodology): “[206] derived from measurements of the cross-correlation of several large-scale structure datasets and the CMB [210] the 2-σ constraints”
Sachs-Wolfe at second order: the CMB bispectrum on large angular scales (2009, background): “This is particularly important in the context of primordial non-Gaussianities: second-order effects are in fact expected to give a signal of order fNL ∼ few, which is not far from the present experimental limits [1, 2, 3].”