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The power spectrum of mass density fluctuations is evaluated from the Mark III and the SFI catalogs of peculiar velocities by a maximum likelihood analysis, using parametric models for the power spectrum and for the errors. The applications…

Astrophysics · Physics 2007-05-23 Idit Zehavi , Avishai Dekel

The power spectrum of mass density fluctuations is estimated from the Mark III and the SFI catalogs of peculiar velocities by applying a maximum likelihood analysis, using parametric models for the power spectrum and for the errors.…

Astrophysics · Physics 2007-05-23 Idit Zehavi

This is a brief progress report on a long-term collaborative project to measure the power spectrum (PS) of mass density fluctuations from the Mark III and the SFI catalogs of peculiar velocities. The PS is estimated by applying maximum…

Astrophysics · Physics 2007-05-23 Idit Zehavi

We determine the linear amplitude of mass fluctuations in the universe, sigma_8, from the abundance of massive clusters at redshifts z=0.5 to 0.8. The evolution of massive clusters depends exponentially on the amplitude of mass fluctuations…

Astrophysics · Physics 2009-11-07 Neta A. Bahcall , Paul Bode

The power spectrum (PS) of mass density fluctuations, independent of `biasing', is estimated from the Mark III catalog of peculiar velocities using Bayesian statistics. A parametric model is assumed for the PS, and the free parameters are…

Astrophysics · Physics 2009-10-28 S. Zaroubi , I. Zehavi , A. Dekel , Y. Hoffman , T. Kolatt

The power spectrum (PS) of {\it mass} density fluctuations, independent of ``biasing", is estimated from the Mark3 Catalog of Peculiar Velocities of galaxies using Bayesian statistics. A parametric model is assumed for the PS, and the free…

Astrophysics · Physics 2016-08-30 S. Zaroubi , A. Dekel , Y. Hoffman , T. Kolatt

The amplitude of cosmological density fluctuations, sigma_8, has been studied and estimated by analysing many cosmological observations. The values of the estimates vary considerably between the various probes. However, different estimators…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-19 Roman Juszkiewicz , Hume A. Feldman , J. N. Fry , Andrew H. Jaffe

The power spectrum (PS) of mass density fluctuations, in the range $0.05 \leq k \leq 0.2 \ihmpc$, is derived from the Mark III catalog of peculiar velocities of galaxies, independent of ``biasing". It is computed from the density field as…

Astrophysics · Physics 2016-08-30 Tsafrir Kolatt , Avishai Dekel

The real-space optical depth distribution along the line of sight to the QSO Q1422+231 is recovered from two HIRES spectra. The first two moments of the truncated optical depth distribution are used to constrain the density fluctuation…

Astrophysics · Physics 2009-10-31 Adi Nusser , Martin Haehnelt

We consider constraints on the amplitude of mass fluctuations in the universe, sigma_8, derived from two simple observations: the present number density of clusters and the amplitude of their correlation function. Allowing for the…

Astrophysics · Physics 2007-05-23 James Robinson , Eric Gawiser , Joseph Silk

We estimate the mass density fluctuations power spectrum (PS) on large scales by applying a maximum likelihood technique to the peculiarvelocity data of the recently completed redshift-distance survey of early-type galaxies (ENEAR). The…

We investigate the linear amplitude of mass fluctuations in the universe, $\sigma_8$, and the present mass density parameter of the Universe, $\Omega_\mathrm{m}$, from the statistical strong gravitational lensing. We use the two populations…

Astrophysics · Physics 2014-10-13 Da-Ming Chen

We present a method for determining the rms mass fluctuations on 8 h^-1 Mpc scale, sigma8. The method utilizes the rate of evolution of the abundance of rich clusters of galaxies. Using the Press-Schechter approximation, we show that the…

Astrophysics · Physics 2009-10-30 Xiaohui Fan , Neta A. Bahcall , Renyue Cen

Using mean relative peculiar velocity measurements for pairs of galaxies, we estimate the cosmological density parameter $\Omega_m$ and the amplitude of density fluctuations $\sigma_8$. Our results suggest that our statistic is a robust and…

We describe an attempt to reconstruct the initial conditions for the formation of cosmological large-scale structure. The power spectrum of the primordial fluctuations is affected by bias, nonlinear evolution and redshift-space distortions,…

Astrophysics · Physics 2015-06-24 J. A. Peacock , S. J. Dodds

We compute the power spectrum of galaxy density fluctuations in a recently completed redshift survey of optically-selected galaxies in the southern hemisphere (SSRS2). The amplitude and shape of the SSRS2 power spectrum are consistent with…

Astrophysics · Physics 2009-10-22 L. N. da Costa , M. S. Vogeley , M. J. Geller , J. P. Huchra , C. Park

Cosmological theories for the origin and evolution of structure in the Universe are highly predictive of the form of the angular power spectrum of cosmic microwave background fluctuations. We present new results from a comprehensive study…

Astrophysics · Physics 2007-05-23 Stephen Hancock , Graca Rocha

We estimate the power spectrum of mass density fluctuations from peculiar velocities of galaxies by applying an improved maximum-likelihood technique to the new all-sky SFI catalog. Parametric models are used for the power spectrum and the…

Cosmological implications of the observed large-scale peculiar velocities are reviewed, alone or combined with redshift surveys and CMB data. The latest version of the POTENT method for reconstructing the underlying three-dimensional…

Astrophysics · Physics 2007-05-23 Avishai Dekel

The large-scale maximum at k~0.05 identified in the power-spectrum of galaxy fluctuations provides a co-moving scale for measuring cosmological curvature. In shallow 3D surveys the peak is broad, but appears to be well resolved in 1D, at…

Astrophysics · Physics 2007-05-23 Tom Broadhurst , Andrew H. Jaffe
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