Cosmological Density and Power Spectrum from Peculiar Velocities: Nonlinear Corrections and Principal Component Analysis

Silberman, L.; Dekel, Avishai; Eldar, A.; Zehavi, Idit

doi:10.1086/321663

Cited by 39 publications

(45 citation statements)

References 67 publications

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“…Those analyses also give the high mass fluctuation levels (σ 8 Ω 0.6 m ) around 0.8-1.1 (Table 3 and 4). On the contrary, Silberman et al (2001) found a power deficiency at k = 0.1 hMpc −1 from the ML analysis of the SFI sample, and their density PS and σ 8 Ω 0.6 m are consistent with our results. As shown in Figure 8, the β in the quasi-linear regime is more accurate than that in the linear-regime.…”

Section: Discussionsupporting

confidence: 90%

Power Spectrum of Cosmic Momentum Field Measured from the SFI Galaxy Sample

Park¹,

Park²

2006

ApJ

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We have measured the cosmic momentum power spectrum from the peculiar velocities of galaxies in the SFI sample. The SFI catalog contains field spiral galaxies with radial peculiar velocities derived from the I-band Tully-Fisher relation. As a natural measure of the large-scale peculiar velocity field, we use the cosmic momentum field that is defined as the peculiar velocity field weighted by local number of galaxies. We have shown that the momentum power spectrum can be derived from the density power spectrum for the constant linear biasing of galaxy formation, which makes it possible to estimate β S = Ω 0.6 m /b S parameter precisely where Ω m is the matter density parameter and b S is the bias factor for optical spiral galaxies. At each wavenumber k we estimate β S (k) as the ratio of the measured to the derived momentum power over a wide range of scales (0.026 h −0.21 . The 68% confidence limits include the cosmic variance. We have also estimated the mass density power spectrum. For example, at k = 0.1047 hMpc −1 (λ = 60 h −1 Mpc) we measure Ω, which is lower compared to the high-amplitude power spectra found from the previous maximum likelihood analyses of peculiar velocity samples like Mark III, SFI, and ENEAR.

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Section: Discussionsupporting

confidence: 90%

Power Spectrum of Cosmic Momentum Field Measured from the SFI Galaxy Sample

Park¹,

Park²

2006

ApJ

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“…For h º 0.65, intersection of the velocity power spectrum and Lya P(k) constraints occurs at n [ 0.8, incompatible with the CMB anisotropy constraint. However, an universe would require a low value of ) m D 1 h in any case because of the age constraint for globular cluster stars, and this would push the intersection to higher n. As noted earlier, the velocity power spectrum constraint shown here is probably biased toward high by the non-) m linear e †ects described by Silberman et al (2001).…”

Section: Combining With Other Constraintsmentioning

confidence: 74%

“…The shape parameter constraint is usually compatible with the cluster mass function constraint, at least if one allows for the possibility that the error bar in equation (11) is somewhat too small. However, the velocity power spectrum always implies a higher Ñuctuation amplitude than the cluster mass function, and the two constraints are not consistent within their stated 1 p uncertainties for any combination of n, and h. A recent ) m , analysis by Silberman et al (2001) shows that the discrepancy is probably a result of nonlinear e †ects on the velocity power spectrum, and that correcting for these yields results closer to the cluster constraint. We therefore regard the cluster constraint as more reliable, and we retain the velocity power spectrum curve mainly as a reminder of other data that can be brought to bear on these questions.…”

Section: Combining With Other Constraintsmentioning

confidence: 97%

Constraints on Cosmological Parameters from the Lyα Forest Power Spectrum andCOBEDMR

Phillips

Weinberg

Croft

et al. 2001

ApJ

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We combine COBE DMR measurements of cosmic microwave background (CMB) anisotropy with a recent measurement of the mass power spectrum at redshift z \ 2.5 from Lya forest data to derive constraints on cosmological parameters and test the inÑationary cold dark matter (CDM) scenario of structure formation. By treating the inÑationary spectral index n as a free parameter, we are able to Ðnd successful Ðts to the COBE and Lya forest constraints in models with and without massive neu-) m \ 1 trinos and in models with and without a cosmological constant. Within each class of model, the low-) m combination of COBE and the Lya forest P(k) constrains a parameter combination of the form with di †erent indices for each case. This new constraint breaks some of the degeneracies in ) m hanb) b c, cosmological parameter determinations from other measurements of large-scale structure and CMB anisotropy. The Lya forest P(k) provides the Ðrst measurement of the slope of the linear mass power spectrum on DMpc scales, l \ [2.25^0.18, and it conÐrms a basic prediction of the inÑationary CDM scenario : an approximately scale invariant spectrum of primeval Ñuctuations (n B 1) modulated by a transfer function that bends P(k) toward kn~4 on small scales. Considering additional observational data, we Ðnd that COBE-normalized, models that match the Lya forest P(k) do not match the ) m \ 1 observed masses of rich galaxy clusters, and that models with a cosmological constant provide low-) m the best overall Ðt to the available data, even without the direct evidence for cosmic acceleration from Type Ia supernovae. With our Ðducial parameter choices, the Ñat, models that match COBE and low-) m the Lya forest P(k) also match recent measurements of small-scale CMB anisotropy. Modest improvements in the Lya forest P(k) measurement could greatly restrict the allowable region of parameter space for CDM models, constrain the contribution of tensor Ñuctuations to CMB anisotropy, and achieve a more stringent test of the current consensus model of structure formation.

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“…In order to minimise the influence of poorly understood non-linear effects a non-linear velocity dispersion component σPV is introduced into the diagonal elements of the covariance matrix (Silberman et al 2001). This nuisance parameter is marginalised over in the analysis.…”

Section: Greene 2006)mentioning

confidence: 99%

Searching for modified gravity: scale and redshift dependent constraints from galaxy peculiar velocities

Johnson

Blake

Dossett

et al. 2016

Mon. Not. R. Astron. Soc.

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We present measurements of both scale-and time-dependent deviations from the standard gravitational field equations. These late-time modifications are introduced separately for relativistic and non-relativistic particles, by way of the parameters G matter (k, z) and G light (k, z) using two bins in both scale and time, with transition wavenumber 0.01 Mpc −1 and redshift 1. We emphasize the use of two dynamical probes to constrain this set of parameters, galaxy power spectrum multipoles and the direct peculiar velocity power spectrum, which probe fluctuations on different scales. The multipole measurements are derived from the WiggleZ and BOSS Data Release 11 CMASS galaxy redshift surveys and the velocity power spectrum is measured from the velocity sub-sample of the 6-degree Field Galaxy Survey. We combine with additional cosmological probes including baryon acoustic oscillations, Type Ia SNe, the cosmic microwave background (CMB), lensing of the CMB, and the temperaturegalaxy cross-correlation. Using a Markov Chain Monte Carlo likelihood analysis, we find the inferred best-fit parameter values of G matter (k, z) and G light (k, z) to be consistent with the standard model at the 95% confidence level. Furthermore, accounting for the Alcock-Paczynski effect, we perform joint fits for the expansion history and growth index gamma; we measure γ = 0.665 ± 0.0669 (68% C.L) for a fixed expansion history, and γ = 0.73 +0.08 −0.10 (68% C.L) when the expansion history is allowed to deviate from ΛCDM. With a fixed expansion history the inferred value is consistent with GR at the 95% C.L; alternatively, a 2σ tension is observed when the expansion history is not fixed, this tension is worsened by the combination of growth and SNe data.

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Cosmological Density and Power Spectrum from Peculiar Velocities: Nonlinear Corrections and Principal Component Analysis

Cited by 39 publications

References 67 publications

Power Spectrum of Cosmic Momentum Field Measured from the SFI Galaxy Sample

Power Spectrum of Cosmic Momentum Field Measured from the SFI Galaxy Sample

Constraints on Cosmological Parameters from the Lyα Forest Power Spectrum andCOBEDMR

Searching for modified gravity: scale and redshift dependent constraints from galaxy peculiar velocities

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