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Related papers: Bounding the Hubble flow in terms of the w paramet…

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Risaliti and Lusso have compiled X-ray and UV flux measurements of 1598 quasars (QSOs) in the redshift range $0.036 \leq z \leq 5.1003$, part of which, $z \sim 2.4 - 5.1$, is largely cosmologically unprobed. In this paper we use these QSO…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-28 Narayan Khadka , Bharat Ratra

In this paper, we show that the expansion history of the Universe in power-law cosmology essentially depends on two crucial parameters, namely the Hubble constant $H_{0}$ and deceleration parameter $q$. We find the constraints on these…

General Relativity and Quantum Cosmology · Physics 2014-08-27 Suresh Kumar

Nowadays, according to the observational evidences the curvature parameter of the universe is neglected and spatially flat FLRW model is on the top of interest for cosmologists. However, due to some discrepancies between $\Lambda$-CDM model…

General Relativity and Quantum Cosmology · Physics 2021-09-30 Ali A. Asgari , Amir H. Abbassi

We consider constraints on the Hubble parameter $H_0$ and the matter density parameter $\Omega_{\mathrm{M}}$ from: (i) the age of the Universe based on old stars and stellar populations in the Galactic disc and halo (Cimatti & Moresco…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Indranil Banik , Nick Samaras

We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Omer Farooq , Foram Madiyar , Sara Crandall , Bharat Ratra

In this work we examine what are the cosmological implications of allowing the geometrical curvature density to behave independently from the energy density contents. Using the full data extracted by Planck mission from CMB, combined with…

General Relativity and Quantum Cosmology · Physics 2017-10-02 Ziad Sakr , Alain Blanchard

We propose a new model-independent method to test the cosmic curvature by comparing the proper distance and transverse comoving distance. Using the measurements of Hubble parameter $H(z)$ and angular diameter distance $d_A$, the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-11 H. Yu , F. Y. Wang

We discuss the cosmological degeneracy between the Hubble parameter H(z), the age of the universe and cosmological parameters describing simple variations from the minimal LCDM model. We show that independent determinations of the Hubble…

Astrophysics · Physics 2014-11-18 Daniel G. Figueroa , Licia Verde , Raul Jimenez

We review the increasing evidence for the cosmological relevance of the cold local Hubble flow. New observations, N-body simulations and other theoretical arguments are discussed, supporting our previous suggestion that the cosmological…

Astrophysics · Physics 2009-11-11 Pekka Teerikorpi , Arthur D. Chernin , Yurij V. Baryshev

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Shulei Cao , Joseph Ryan , Narayan Khadka , Bharat Ratra

It is shown, from the two independent approaches of McCrea-Milne and of Zeldovich, that one can fully recover the set equations corresponding to the relativistic equations of the expanding universe of Friedmann-Lemaitre-Robertson-Walker…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 V. G. Gurzadyan , A. Stepanian

Current observational bounds on dark energy depend on assumptions about the curvature of the universe. We present a simple and efficient method for incorporating constraints from CMB anisotropy data, and use it to derive constraints on…

Astrophysics · Physics 2010-04-06 Yun Wang , Pia Mukherjee

Numerous upcoming observations, such as WFIRST, BOSS, BigBOSS, LSST, Euclid, and Planck, will constrain dark energy (DE)'s equation of state with great precision. They may well find the ratio of pressure to energy density, $w$, is -1,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Zachary Slepian , J. Richard Gott , Joel Zinn

Time delays between multiple images of lensed sources can probe the geometry of the universe. We propose a novel method based on free-form modelling of gravitational lenses to estimate time-delay distances and, in turn, cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Mauro Sereno , Danuta Paraficz

We use Cosmic Microwave Background (CMB) observations together with the Red-sequence Cluster Survey (RCS) weak lensing results to derive constraints on a range of cosmological parameters. This particular choice of observations is motivated…

Astrophysics · Physics 2008-11-26 Carlo R. Contaldi , Henk Hoekstra , Antony Lewis

In this paper, we propose an improved model-independent method to constrain the cosmic curvature by combining the most recent Hubble parameter $H(z)$ and supernovae Ia (SNe Ia) data. Based on the $H(z)$ data, we first use the…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Jun-Jie Wei , Xue-Feng Wu

Future large ensembles of time delay lenses have the potential to provide interesting cosmological constraints complementary to those of other methods. In a flat universe with constant w including a Planck prior, LSST time delay…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Dan Coe , Leonidas Moustakas

A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of the…

General Relativity and Quantum Cosmology · Physics 2018-07-04 J. K. Singh , Kazuharu Bamba , Ritika Nagpal , S. K. J. Pacif

A new method is proposed to measure the Hubble constant H0 through the mean transmitted flux observed from high redshift quasars. A semi-analytical model for the cosmological-independent volume density distribution function is adopted which…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 V. C. Busti , R. N. Guimarães , J. A. S. Lima

One of the most compelling tasks of modern cosmology is to constrain the expansion history of the Universe, since this measurement can give insights on the nature of dark energy and help to estimate cosmological parameters. In this letter…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-24 Michele Moresco