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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

We examine the dependence of the mass-to-light (M/L) ratio of large-scale structure on cosmological parameters, in models that are constrained to match observations of the projected galaxy correlation function w(rp). For a sequence of…

Astrophysics · Physics 2010-04-06 Jeremy L. Tinker , David H. Weinberg , Zheng Zheng , Idit Zehavi

An intriguing discrepancy emerging in the concordance model of cosmology is the tension between the locally measured value of the Hubble rate, and the 'global' value inferred from the cosmic microwave background (CMB). This could be due to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Vinicius C. Busti , Chris Clarkson , Marina Seikel

Cosmology faces a pressing challenge with the Hubble constant ($H_0$) tension, where the locally measured rate of the Universe's expansion does not align with predictions from the cosmic microwave background (CMB) calibrated with…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Rebecca Briffa , Celia Escamilla-Rivera , Jackson Levi Said , Jurgen Mifsud

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

We have assembled a compilation of observational Hubble parameter measurements estimated with the differential evolution of cosmic chronometers, in the redshift range 0<z<1.75. This sample has been used, in combination with CMB data and…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-06 Michele Moresco , Licia Verde , Lucia Pozzetti , Raul Jimenez , Andrea Cimatti

The cosmic acceleration observed in the expansion of the Universe has sparked extensive research into the nature of dark energy, which is known to constitute approximately 70\% of the Universe's energy content. In this study, we explore two…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-26 M. Koussour , N. S. Kavya , V. Venkatesha , N. Myrzakulov

We provide preliminary quantitative evidence that a new solution to averaging the observed inhomogeneous structure of matter in the universe [gr-qc/0702082, arxiv:0709.0732], may lead to an observationally viable cosmology without exotic…

Astrophysics · Physics 2008-11-26 Ben M. Leith , S. C. Cindy Ng , David L. Wiltshire

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 investigate whether the current Hubble parameter $H(z)$ measurements could help improve the constraints on dark energy on the basis of the mainstream cosmological probes including the type Ia supernovae (SN) observation, the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-16 Yan Liu , Rui-Yun Guo , Jing-Fei Zhang , Xin Zhang

We use some of the recently released observational data to test the viability of two classes of minimally coupled scalar field models of quintessence with exponential potentials for which exact solutions of the Einstein equations are known.…

Astrophysics · Physics 2009-11-10 M. Demianski , E. Piedipalumbo , C. Rubano , C. Tortora

New, large, ground and space telescopes are contributing to an exciting and rapid period of growth in observational cosmology. The subject is now far from its earlier days of being data-starved and unconstrained, and new data are fueling a…

Astrophysics · Physics 2009-11-07 Wendy L. Freedman

We measure the current expansion rate of the Universe, Hubble's constant $H_0$, by calibrating the absolute magnitudes of supernovae to distances measured by Baryon Acoustic Oscillations. This `inverse distance ladder' technique provides an…

We present an extensive comparison of models of structure formation with observations, based on linear and quasi-linear theory. We assume a critical matter density, and study both cold dark matter models and cold plus hot dark matter…

Astrophysics · Physics 2015-06-24 Andrew R Liddle , David H Lyth , R K Schaefer , Q Shafi , Pedro T P Viana

The cosmological parameters that I will emphasize are the Hubble parameter $H_0 \equiv 100 h$ km s$^{-1}$ Mpc$^{-1}$, the age of the universe $t_0$, the average matter density $\Omega_m$, the baryonic matter density $\Omega_b$, the neutrino…

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

We propose that dark matter (DM) possesses a quadratic equation of state, which becomes significant at high densities, altering the Universe's evolution during its early stages. We derive the modified background evolution equations for the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-02 Kazem Rezazadeh , Ebrahim Yusofi , Alireza Talebian

We investigate the possibility of measuring the Hubble constant, the fractional energy density components and the equation of state parameter of the ``dark energy'' using lensed multiple images of high-redshift supernovae. With future…

Astrophysics · Physics 2009-11-07 A. Goobar , E. Mortsell , R. Amanullah , P. Nugent

The results of different analyses of the dynamical parameters of the Universe are converging towards agreement. Remaining disagreements reflect systematic errors coming either from the observations or from differences in the methods of…

Astrophysics · Physics 2007-05-23 Matts Roos , S. M. Harun-or-Rashid

We propose a Bayesian meta-analysis to infer the current expansion rate of the Universe, called the Hubble constant ($H_0$), via time delay cosmography. Inputs of the meta-analysis are estimates of two properties for each pair of…

Applications · Statistics 2024-11-14 Hyungsuk Tak , Xuheng Ding

We study the linear and non-linear bias parameters which determine the mapping between the distributions of galaxies and the full matter density fields, comparing different measurements and predictions. Associating galaxies with dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Kai Hoffmann , Julien Bel , Enrique Gaztanaga
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