Scale-dependent bias from the reconstruction of non-Gaussian distributions

Chongchitnan, Sirichai; Silk, Joseph

doi:10.1103/physrevd.83.083504

Cited by 13 publications

(17 citation statements)

References 59 publications

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“…A similar scale-dependent halo bias has been reported in the presence of the primordial trispectrum (see [42][43][44][45] for g nl -type and [45][46][47] for τ nl -type). Furthermore, the scale dependence in the halo bias is found to be present in other models of the primordial non-Gaussianities, such as the scale-dependent f nl model [48,49], ungaussiton model [50], and non-local non-Gaussian models [51][52][53].…”

Section: Introductionsupporting

confidence: 76%

Scale dependence of the halo bias in general local-type non-Gaussian models I: analytical predictions and consistency relations

Nishimichi

2012

J. Cosmol. Astropart. Phys.

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Abstract. We investigate the clustering of halos in cosmological models starting with general local-type non-Gaussian primordial fluctuations. We employ multiple Gaussian fields and add local-type non-Gaussian corrections at arbitrary order to cover a class of models described by frequently-discussed f nl , g nl and τ nl parameterization. We derive a general formula for the halo power spectrum based on the peak-background split formalism. The resultant spectrum is characterized by only two parameters responsible for the scale-dependent bias at large scale arising from the primordial non-Gaussianities in addition to the Gaussian bias factor. We introduce a new inequality for testing non-Gaussianities originating from multi fields, which is directly accessible from the observed power spectrum. We show that this inequality is a generalization of the Suyama-Yamaguchi inequality between f nl and τ nl to the primordial non-Gaussianities at arbitrary order. We also show that the amplitude of the scale-dependent bias is useful to distinguish the simplest quadratic non-Gaussianities (i.e., f nl -type) from higher-order ones (g nl and higher), if one measures it from multiple species of galaxies or clusters of galaxies. We discuss the validity and limitations of our analytic results by comparison with numerical simulations in an accompanying paper.

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Section: Introductionsupporting

confidence: 76%

Scale dependence of the halo bias in general local-type non-Gaussian models I: analytical predictions and consistency relations

Nishimichi

2012

J. Cosmol. Astropart. Phys.

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“…Observational constraints on the bispectrum are given in [1] while constraints on g NL are given in [52,53] (see also [54]) and for both g NL and τ NL in [55]. Forecasts for future constraints on all three parameters are given in [56,57] while forecast constraints on n fNL are given in [16].…”

Section: Two Field Models Of Inflationmentioning

confidence: 99%

Scale-dependent non-Gaussianity probes inflationary physics

Byrnes

Gerstenlauer

Nurmi

et al. 2010

J. Cosmol. Astropart. Phys.

109

136

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Abstract:We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new observable parameters. They can help to discriminate between models of inflation, since they are sensitive to properties of the inflationary physics that are not probed by the standard observables. We find consistency relations between these parameters in certain classes of models. We apply our results to a scenario of modulated reheating, showing that the scale dependence of non-Gaussianity can be significant. We also discuss the scale dependence of the bispectrum and trispectrum, in cases where one varies the shape as well as the overall scale of the figure under consideration. We conclude providing a formulation of the curvature perturbation in real space, which generalises the standard local form by dropping the assumption that f NL and g NL are constants.

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“…Further potentially interesting cosmological applications of the 21 cm forest include probes of primordial non-Gaussianity in relation to either the nonlinear, scale-dependent bias [64] or the halo mass function [65], and probes of isocurvature primordial perturbations (e.g [66]). We note that several recent papers have discussed the possibility of studying various aspects of the SSPS via the 21 cm emission signal [67], although efficient removal of the far brighter foreground emission poses a major observational challenge for realizing such prospects [29].…”

Section: Discussion and Summarymentioning

confidence: 99%

Probing small-scale cosmological fluctuations with the 21 cm forest: Effects of neutrino mass, running spectral index, and warm dark matter

et al. 2014

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Although the cosmological paradigm based on cold dark matter and adiabatic, nearly scaleinvariant primordial fluctuations is consistent with a wide variety of existing observations, it has yet to be sufficiently tested on scales smaller than those of massive galaxies, and various alternatives have been proposed that differ significantly in the consequent small-scale power spectrum (SSPS) of large-scale structure. Here we show that a powerful probe of the SSPS at k 10 Mpc −1 can be provided by the 21 cm forest, that is, systems of narrow absorption lines due to intervening, cold neutral hydrogen in the spectra of high-redshift background radio sources in the cosmic reionization epoch. Such features are expected to be caused predominantly by collapsed gas in starless minihalos, whose mass function can be very sensitive to the SSPS. As specific examples, we consider the effects of neutrino mass, running spectral index (RSI) and warm dark matter (WDM) on the SSPS, and evaluate the expected distribution in optical depth of 21 cm absorbers out to different redshifts. Within the current constraints on quantities such as the sum of neutrino masses mν, running of the primordial spectral index dns/d ln k and WDM particle mass mWDM, the statistics of the 21 cm forest manifest observationally significant differences that become larger at higher redshifts. In particular, it may be possible to probe the range of mWDM 10 keV that may otherwise be difficult to access. Future observations of the 21 cm forest by the Square Kilometer Array may offer a unique and valuable probe of the SSPS, as long as radio sources such as quasars or Population III gamma-ray bursts with sufficient brightness and number exist at redshifts of z 10 -20, and the astrophysical effects of reionization and heating can be discriminated.PACS numbers: 98.70. Vc, 98.80.Es

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Scale-dependent bias from the reconstruction of non-Gaussian distributions

Cited by 13 publications

References 59 publications

Scale dependence of the halo bias in general local-type non-Gaussian models I: analytical predictions and consistency relations

Scale dependence of the halo bias in general local-type non-Gaussian models I: analytical predictions and consistency relations

Scale-dependent non-Gaussianity probes inflationary physics

Probing small-scale cosmological fluctuations with the 21 cm forest: Effects of neutrino mass, running spectral index, and warm dark matter

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