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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…

宇宙学与河外天体物理 · 物理学 2014-03-31 Wei Zheng , Hong Li , Jun-Qing Xia , You-Ping Wan , Si-Yu Li , Mingzhe Li

In this paper, we investigate the possibility that the Universe is driven by a single dark fluid described by a Lambert $W$ equation of state parameter, $w_{eff}$, which is essentially dependent on two parameters $\vartheta_{1}$ and…

广义相对论与量子宇宙学 · 物理学 2022-02-14 Abdulla Al Mamon , Subhajit Saha

In the present work, we have studied the dynamics of accelerating universe considering a simple parametrization of the equation of state parameter in an interacting scenario. In this toy model, the dark energy component is allowed to…

广义相对论与量子宇宙学 · 物理学 2025-05-23 Sangita Goswami , Sudipta Das

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…

天体物理学 · 物理学 2007-05-23 Joel R. Primack

We determine a cosmological model that include a positive acceleration of the Universe and a time decreasing fine structure constant. The present day deceleration parameter is estimated by us, according to our model and the available…

广义相对论与量子宇宙学 · 物理学 2007-05-23 Marcelo S. Berman , Luis A. Trevisan

To recreate the cosmological models, we employed the parametrization approach in modified teleparallel Gauss-Bonnet gravity. It has been interesting to apply the parametrization approach to investigate cosmological models. The real benefit…

广义相对论与量子宇宙学 · 物理学 2022-12-29 Santosh V. Lohakare , B. Mishra , S. K. Maurya , Ksh. Newton Singh

In this work, the cosmic solutions, particularly the well-known $\Lambda$CDM model, are investigated in the framework of the Gauss-Bonnet gravity, where the gravitational action incorporates the Gauss-Bonnet invariant function. We utilize a…

广义相对论与量子宇宙学 · 物理学 2024-09-26 N. Myrzakulov , Anirudh Pradhan , Archana Dixit , S. H. Shekh

We further investigate slowing down of acceleration of the universe scenario for five parametrizations of the equation of state of dark energy using four sets of supernovae data. In a maximal probability analysis we also use the baryon…

宇宙学与河外天体物理 · 物理学 2016-08-08 Juan Magaña , Víctor H. Cárdenas , V. Motta

The accelerating expansion of the universe is the most surprising cosmological discovery in many decades. In this short review, we briefly summarize theories for the origin of cosmic acceleration and the observational methods being used to…

宇宙学与河外天体物理 · 物理学 2014-01-03 Michael J. Mortonson , David H. Weinberg , Martin White

We investigate a dark energy (DE) equation of state (EoS) parametrization in a curved spacetime using current observations. We constrain the model parameters by using observational Hubble data from Cosmic Chronometer (CC), Pantheon Plus…

综合物理 · 物理学 2026-05-13 D. Revanth Kumar , Santosh Kumar Yadav

We study the accelerated expansion phase of the universe by using the {\textit{kinematic approach}}. In particular, the deceleration parameter $q$ is parametrized in a model-independent way. Considering a generalized parametrization for…

广义相对论与量子宇宙学 · 物理学 2018-10-22 Abdulla Al Mamon , Kazuharu Bamba

The current observations are usually explained by an accelerating expansion of the present universe. However, with the present quality of the supernovae Ia data, the allowed parameter space is wide enough to accommodate the decelerating…

天体物理学 · 物理学 2009-11-07 R. G. Vishwakarma

We revisit the evolution of cosmic acceleration in a spatially flat $w_0w_a$CDM universe, in which the equation of state of dark energy takes the CPL parametrization, using the latest baryon acoustic oscillation (BAO) measurements from the…

宇宙学与河外天体物理 · 物理学 2025-08-12 Jincheng Wang , Hongwei Yu , Puxun Wu

The Hubble constant ($H_0$), which represents the expansion rate of the Universe, is one of the most important cosmological parameters. The recent measurements of $H_0$ using the distance ladder methods such as Type Ia Supernovae (SNe Ia)…

宇宙学与河外天体物理 · 物理学 2023-06-14 Rahul Kumar Thakur , Shashikant Gupta , Rahul Nigam , PK Thiruvikraman

In this study, we have explored a transitioning cosmological model of universe's expansion in $f(R,\mathcal{L}_{m})$ gravity. The quadratic type of equation of state parameter in the form $\omega=-1 + \alpha (1 + z) + \beta (1 + z)^2$,…

广义相对论与量子宇宙学 · 物理学 2025-04-16 Vinod Kumar Bhardwaj , Saibal Ray

We scrutinized the Locally Rotational Symmetry (LRS) Bianchi type-I cosmological model in the presence of fractional holographic dark energy. We calculate the value of the Hubble parameter $H(z)$ using the field equations. After that, we…

广义相对论与量子宇宙学 · 物理学 2025-06-23 Shivangi Rathore , Elangbam Chingkheinganba Meetei , S. Surendra Singh

In the current study, we investigate a scalar field cosmological model with Lyra's geometry to explain the present cosmic expansion in a homogeneous and isotropic flat FRW universe. In Einstein's field equations, we presupposed a variable…

广义相对论与量子宇宙学 · 物理学 2025-11-19 Vinod Kumar Bhardwaj , Anil Kumar Yadav , Lalit Kumar Gupta , Rajendra Prasad , Sudhir Kumar Srivastava

In this research work, we explore the late-time accelerated expansion of the universe within the framework of modified gravity, specifically $f(R, L_m)$ theory, by considering two non-linear models: $f(R, L_{m}) = \frac{R}{2}+(1+\eta R)…

广义相对论与量子宇宙学 · 物理学 2025-06-23 Khomesh R. Patle , G. P. Singh , Romanshu Garg

The possibility of an expanding decelerating Universe in the distant future is investigated in the context of a quintessence scalar field cosmology. Such a conceivable evolution is tested against SNe Ia and $H(z)$ cosmic chronometers data,…

宇宙学与河外天体物理 · 物理学 2024-01-29 A. A. Escobal , J. F. Jesus , S. H. Pereira , J. A. S. Lima

A new cosmological model makes the following predictions: (1) The deceleration parameter $q_{0}$ is approximately zero. (2) The mass density parameter $\Omega_{m}$ is less than 1. (3) The universe is spatially closed, but is asymptotically…

天体物理学 · 物理学 2009-10-31 R. E. Allen