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Aiming at exploring the nature of dark energy (DE), we use forty-three observational Hubble parameter data (OHD) in the redshift range $0 < z \leqslant 2.36$ to make a cosmological model-independent test of the $\Lambda$CDM model with…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-13 Shu-Lei Cao , Xiao-Wei Duan , Xiao-Lei Meng , Tong-Jie Zhang

Aiming at exploring the nature of dark energy, we use thirty-six observational Hubble parameter data (OHD) in the redshift range $0 \leqslant z \leqslant 2.36$ to make a cosmological model-independent test of the two-point…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-10 Xiao-Lei Meng , Xin Wang , Shi-Yu Li , Tong-Jie Zhang

We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 Shulei Cao , Bharat Ratra

In this article, we employ a machine learning (ML) approach for the estimations of four fundamental parameters, namely, the Hubble constant ($H_0$), matter ($\Omega_{0m}$), curvature ($\Omega_{0k}$) and vacuum ($\Omega_{0\Lambda}$)…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Srikanta Pal , Rajib Saha

Direct measurements of Hubble parameters $H(z)$ are very useful for cosmological model parameters inference. Based on them, Sahni, Shafieloo and Starobinski introduced a two-point diagnostic $Omh^2(z_i, z_j)$ as an interesting tool for…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Xiaogang Zheng , Marek Biesiada , Xuheng Ding , Shuo Cao , Sixuan Zhang , Zong-Hong Zhu

In this paper, we have investigated late time acceleration for a spatially flat dust filled Universe in Brans-Dicke theory in the presence of a positive cosmological constant $\Lambda$ . Expressions for Hubble's constant, luminosity…

General Relativity and Quantum Cosmology · Physics 2017-10-23 G. K. Goswami

The cosmological parameters that I discuss are the Hubble parameter $H_0 \equiv 100 h$ km s$^{-1}$ Mpc$^{-1}$, the age of the universe $t_0$, the average density $\Omega_0$, and the cosmological constant $\Lambda$. To focus the discussion,…

Astrophysics · Physics 2007-05-23 Joel R. Primack

We use 28 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07 \leq z \leq 2.3$ to determine the present-day Hubble constant $H_0$ in four cosmological models. We measure $H_0 = 68.3^{ +2.7}_{ -2.6 }, 68.4^{ +2.9 }_{ -3.3…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-26 Yun Chen , Suresh Kumar , Bharat Ratra

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 paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-31 Wei Zheng , Hong Li , Jun-Qing Xia , You-Ping Wan , Si-Yu Li , Mingzhe Li

We derive constraints on cosmological parameters using the power spectrum of galaxy clustering measured from the final two-degree field galaxy redshift survey (2dFGRS) and a compilation of measurements of the temperature power spectrum and…

I discuss the Hubble parameter $H_0$, the age of the universe $t_0$, the density $\Omega_0$, and the cosmological constant $\Lambda$. To focus the discussion, I concentrate on the issue of the value of the density $\Omega_0$ in currently…

Astrophysics · Physics 2016-08-30 Joel R. Primack

Recent cosmic microwave background (CMB) measurements over a large range of angular scales have become sensitive enough to provide interesting constraints on cosmological parameters within a restricted class of models. We use the CMB…

Astrophysics · Physics 2008-02-03 Charles H. Lineweaver , Domingos Barbosa

We explore recent estimations of the Hubble parameter $H$ depending on redshift $z$, which include 31 $H(z)$ data points measured from differential ages of galaxies and 26 data points, obtained with other methods. We describe these data…

General Relativity and Quantum Cosmology · Physics 2018-07-20 G. S. Sharov , V. O. Vasiliev

We use the dispersion measure (DM) and redshift measurements of 24 localized fast radio bursts (FRBs) to compare cosmological models and investigate the Hubble tension. Setting a flat prior on the DM contribution from the Milky Way's halo,…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-14 Jun-Jie Wei , Fulvio Melia

We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-27 Jia-Jia Geng , Rui-Yun Guo , Anzhong Wang , Jing-Fei Zhang , Xin Zhang

We use three different data sets, specifically $H(z)$ measurements from cosmic chronometers, the HII-galaxy Hubble diagram, and reconstructed quasar-core angular-size measurements, to perform a joint analysis of three flat cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-01 Hao-Yi Wan , Shu-Lei Cao , Fulvio Melia , Tong-Jie Zhang

In this review, the status of measurements of the matter density (Omega), the vaccuum energy density or cosmological constant (Lambda), the Hubble constant (H0), and ages of the oldest measured objects (t0) are summarized. Measurements of…

Astrophysics · Physics 2009-10-30 Wendy L. Freedman

Recent measurements of the parameters of the Concordance Cosmology Model ($\Lambda$CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done with Cosmic Microwave Background (CMB) imply different…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 B. Czerny , M. L. Martínez-Aldama , G. Wojtkowska , M. Zajaček , P. Marziani , D. Dultzin , M. H. Naddaf , S. Panda , R. Prince , R. Przyluski , M. Ralowski , M. Śniegowska

Within the $\Lambda$CDM cosmological model, the absolute value of Einstein's cosmological constant $\Lambda$, sometimes expressed as the gravitating mass-energy density $\rho_\Lambda$ of the physical vacuum, is a fundamental constant of…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 J. Prat , C. Hogan , C. Chang , J. Frieman
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