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We show how the cosmological constant can be estimated from redshift surveys at different redshifts, using maximum-likelihood techniques. The apparent redshift-space clustering on large scales (\simgt 20 \himpc) are affected in the radial…

Astrophysics · Physics 2009-11-06 Takahiko Matsubara , Alexander S. Szalay

When the 2dF QSO Redshift Survey (2QZ) is complete, a powerful geometric test for the cosmological constant will be available. By comparing the clustering along and across the line of sight and modelling the effects of peculiar velocities…

Astrophysics · Physics 2009-11-06 P. J. Outram , Fiona Hoyle , T. Shanks , B. J. Boyle , S. M. Croom , N. S. Loaring , L. Miller , R. J. Smith

Gravitational lensing can provide pure geometric tests of the structure of space-time, for instance by determining empirically the angular diameter distance-redshift relation. This geometric test has been demonstrated several times using…

We revisit the feasibility of a cosmological test with the geometric distortion focusing on an ambiguous factor of the evolution of bias. Starting from defining estimators for the spatial two-point correlation function and the power…

Astrophysics · Physics 2007-05-23 Kazuhiro Yamamoto , Hiroaki Nishioka , Atsushi Taruya

We study constraints that anticipated DEEP survey galaxy counts versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. This data will result…

Astrophysics · Physics 2011-07-19 Silviu Podariu , Bharat Ratra

Redshift distortions, both geometrical and kinematical, of quasar clustering are simulated, for the Two-Degree Field QSO Redshift Survey (2QZ), showing that they are very effective to constrain the cosmological density and equation of state…

Astrophysics · Physics 2007-05-23 M. O. Calvao , J. R. T. de Mello Neto , I. Waga

I discuss two cosmological tests to determine the cosmological density parameter \Omega_0 the cosmological constant \lambda_0, which make use of the anisotropy of the two-point correlation functions due to the peculiar velocity field and…

Astrophysics · Physics 2007-05-23 Yasushi Suto

The lensing effect of curved space, which can cause the angular diameter of a fixed reference length seen on the sky to reach a minimum and then increase with redshift, depends sensitively on the value of the cosmological constant,…

High Energy Physics - Phenomenology · Physics 2009-10-22 Lawrence M. Krauss , David Schramm

We propose cosmological redshift-space distortion of correlation functions of galaxies and quasars as a probe of both the density parameter $\Omega_0$ and the cosmological constant $\lambda_0$. In particular, we show that redshift-space…

Astrophysics · Physics 2009-10-28 Takahiko Matsubara , Yasushi Suto

We investigate the impact of different observational effects affecting a precise and accurate measurement of the growth rate of fluctuations from the anisotropy of clustering in galaxy redshift surveys. We focus on redshift measurement…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-23 Federico Marulli , Davide Bianchi , Enzo Branchini , Luigi Guzzo , Lauro Moscardini , Raul E. Angulo

The large-scale structure in the distribution of galaxies is thought to arise from the gravitational instability of small fluctuations in the initial density field of the universe. A key test of this hypothesis is that superclusters of…

The clustering of galaxies observed in future redshift surveys will provide a wealth of cosmological information. Matching the signal at different redshifts constrains the dark energy driving the acceleration of the expansion of the…

We report on measurements of the cosmological constant, Lambda, and the redshift space distortion parameter beta=Omega_m^0.6/b, based on an analysis of the QSO power spectrum parallel and perpendicular to the observer's line of sight, from…

Astrophysics · Physics 2009-11-10 P. J. Outram , T. Shanks , B. J. Boyle , S. M. Croom , Fiona Hoyle , N. S. Loaring , L. Miller , R. J. Smith

We investigate the cosmological dependence and the constraining power of large-scale galaxy correlations, including all redshift-distortions, wide-angle, lensing and gravitational potential effects on linear scales. We analyze the…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 Alvise Raccanelli , Francesco Montanari , Daniele Bertacca , Olivier Doré , Ruth Durrer

Redshift space distortion (RSD) observed in galaxy redshift surveys is a powerful tool to test gravity theories on cosmological scales, but the systematic uncertainties must carefully be examined for future surveys with large statistics.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Takashi Ishikawa , Tomonori Totani , Takahiro Nishimichi , Ryuichi Takahashi , Naoki Yoshida , Motonari Tonegawa

In models with a cosmological constant, a significant component of the large scale cosmic microwave background (CMB) anisotropy is produced at rather low redshifts, z < 1. In these models, the gravitational potential perturbations begin to…

Astrophysics · Physics 2009-07-09 Robert G. Crittenden , Neil Turok

Kaiser redshift-space distortion formula describes well the clustering of galaxies in redshift surveys on small scales, but there are numerous additional terms that arise on large scales. Some of these terms can be described using Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Jaiyul Yoo , Nico Hamaus , Uros Seljak , Matias Zaldarriaga

Recent cosmological tensions pose difficulties for $\Lambda$CDM. Forthcoming facilities will be able to check whether these tensions result from systematic effects or indeed with the $\Lambda$CDM model itself. However, these new data will…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-12 Dinko Milaković , John K. Webb

Cosmography is a model-independent phenomenological approach to observational cosmology, relying on Taylor series expansions of physical quantities as a function of the cosmological redshift or other analogous variables. A recent work…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-27 C. J. A. P. Martins

Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the…

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