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We present new limits on cosmological parameters from the statistics of gravitational lensing, based on the recently revised knowledge of the luminosity function and internal dynamics of E/S0 galaxies that are essential in lensing…

Astrophysics · Physics 2009-10-30 Masashi Chiba , Yuzuru Yoshii

Keeping in mind the current picture of an accelerating and flat Universe, some specific dynamical models of the cosmological term $\Lambda$ have been selected for investigating the nature of dark energy. Connecting the free parameters of…

Astrophysics · Physics 2008-11-26 Saibal Ray , Utpal Mukhopadhyay , Xin-He Meng

We improve strong lensing constraints on cosmological parameters in light of the new measurement of the velocity dispersion function of early-type galaxies based on the SDSS DR5 data and recent semi-analytical modeling of galaxy formation.…

Astrophysics · Physics 2009-11-11 Kyu-Hyun Chae

We use three strong lensing clusters to constrain the cosmological parameters Omega_m and Omega_lambda. Recent HST observations of galaxy clusters reveal a large number of multiple images, which are predicted to be at different redshifts.…

Astrophysics · Physics 2007-05-23 G. Golse , J. -P. Kneib , G. Soucail

Six challenges for the standard cosmological model $\Lambda$CDM are listed, which arise when comparing theoretical predictions with observational data on scales of ~1 Mpc. Different parameters of luminous and dwarf galaxies in the local…

General Relativity and Quantum Cosmology · Physics 2026-05-29 I. D. Karachentsev

Fourteen classical double radio galaxies with redshifts between zero and two were used to determine the cosmological parameters $\Omega_m$, $\Omega_{\Lambda}$, and $\Omega_k$, where these are the normalized values of the mean mass density,…

Astrophysics · Physics 2007-05-23 Ruth A. Daly , E. J. Guerra , Lin Wan

There is currently no consistent approach to modelling galaxy bias evolution in cosmological inference. This lack of a common standard makes the rigorous comparison or combination of probes difficult. We show that the choice of biasing…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 L. Clerkin , D. Kirk , O. Lahav , F. B. Abdalla , E. Gaztanaga

We study dynamics of $\Lambda(t)$ cosmological models which are a natural generalization of the standard cosmological model (the $\Lambda$CDM model). We consider a class of models: the ones with a prescribed form of…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-29 Marek Szydlowski , Aleksander Stachowski

This paper advances a general proposal for testing non-standard cosmological models by means of observational relations of cosmological point sources in some specific waveband, and their use in the context of the data provided by the galaxy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Marcelo B. Ribeiro

We study the impact of the cosmological parameters uncertainties on the measurements of primordial non-Gaussianity through the large-scale non-Gaussian halo bias effect. While this is not expected to be an issue for the standard LCDM model,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Carmelita Carbone , Olga Mena , Licia Verde

Measurements of the cosmological density parameter (Omega) using techniques that exploit the gravity-induced motions of galaxies yield, in linear perturbation theory, the degenerate parameter combination beta=Omega^{0.6}/b, where the linear…

Astrophysics · Physics 2007-05-23 Andreas A. Berlind , Vijay K. Narayanan , David H. Weinberg

The estimation of cosmological parameters from a given data set requires a construction of a likelihood function which, in general, has a complicated functional form. We adopt a Gaussian copula and constructed a copula likelihood function…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-28 Masanori Sato , Kiyotomo Ichiki , Tsutomu T. Takeuchi

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

Measurements of the cosmological density parameter Omega using techniques that exploit the gravity-induced motions of galaxies constrain, in linear perturbation theory, the degenerate parameter combination beta = Omega^{0.6}/b, where the…

Astrophysics · Physics 2011-08-23 Andreas A. Berlind , Vijay K. Narayanan , David H. Weinberg

Problems with the concordance cosmology $\Lambda$CDM as the cosmological constant problem, coincidence problems and Hubble tension has led to many proposed alternatives, as the $\Lambda(t)$CDM, where the now called $\Lambda$ cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-03 H. A. P. Macedo , L. S. Brito , J. F. Jesus , M. E. S. Alves

Recent observations of high-redshift Type Ia supernovae have placed stringent constraints on the cosmological constant $\Lambda$. We explore the implications of these SNe observations for cosmological models in which a classically evolving…

Astrophysics · Physics 2009-10-30 Joshua A. Frieman , Ioav Waga

Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as the cosmological model, and galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Rachel Reddick , Jeremy Tinker , Risa Wechsler , Yu Lu

In this paper we investigate the statistical properties of gravitational lenses for models in which a cosmological term decreases with time as $\Lambda \propto a^{-m}$, where $a$ is the scale factor and $m$ is a parameter ($0 \leq m < 3$).…

Astrophysics · Physics 2015-06-24 L. F. Bloomfield Torres , I. Waga

Under the assumption that the gas mass fraction of galaxy clusters estimated out to an outer hydrostatic radius is constant, it is possible to constrain the cosmological parameters by using the angular diameter distance relation with…

Astrophysics · Physics 2011-05-23 Asantha R. Cooray

Constraints on the main cosmological parameters using CMB or large scale structure data are usually based on power-law assumption of the primordial power spectrum (PPS). However, in the absence of a preferred model for the early universe,…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-14 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep