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相关论文: Constraining cosmic deceleration-acceleration tran…

200 篇论文

In the paper, we present an accelerating cosmological model in $f(R,\mathcal{L}_{m})$ gravity with the parameter constrained through the cosmological data sets. At the beginning, we have employed a functional form of $f(R,\mathcal{L}_{m})…

广义相对论与量子宇宙学 · 物理学 2025-01-10 Y. Kalpana Devi , S. A. Narawade , B. Mishra

In this article, we introduce an innovative parametric representation of the Hubble parameter, providing a model-independent means to explore the dynamics of an accelerating cosmos. The model's parameters are rigorously constrained through…

宇宙学与河外天体物理 · 物理学 2024-04-16 M. Koussour , N. Myrzakulov , M. K. M. Ali

In this paper, we have considered a spatially flat FRW universe filled with pressureless matter and dark energy. We have considered a phenomenological parametrization of the deceleration parameter $q(z)$ and from this we have reconstructed…

广义相对论与量子宇宙学 · 物理学 2017-03-22 Abdulla Al Mamon , Sudipta Das

In this work, we perform observational data analysis on Einsteinian cubic gravity and $f(P)$ gravity to constrain the parameter space of the theories. We use the 30-point $z-H(z)$ cosmic chronometer data as the observational tool for our…

宇宙学与河外天体物理 · 物理学 2022-06-14 Kinsuk Giri , Prabir Rudra

Kinematical models are constrained by the latest observational data from geometry-distance measurements, which include 557 type Ia supernovae (SNIa) Union2 data and 15 observational Hubble data. Considering two parameterized deceleration…

宇宙学与河外天体物理 · 物理学 2015-05-28 Jianbo Lu , Lixin Xu , Molin Liu

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

We compile a complete collection of reliable Hubble parameter $H(z)$ data to redshift $z \leq 2.36$ and use them with the Gaussian Process method to determine continuous $H(z)$ functions for various data subsets. From these continuous…

宇宙学与河外天体物理 · 物理学 2018-04-04 Hai Yu , Bharat Ratra , Fa-Yin Wang

This study examines five models derived from the Pacif parametrization scheme of the Hubble parameter ($H$), yielding various linear to quintic forms of the deceleration parameter (DP). Our goal is to explore the impact of these DP…

宇宙学与河外天体物理 · 物理学 2024-12-13 Himanshu Chaudhary , Shibesh Kumar Jas Pacif , G. Mustafa , Amine Bouali , Faisal Javed

The free parameters of a flat accelerating model without dark energy are constrained by using Supernovae type Ia and observational H(z) data. Instead of the vacuum dominance, the present accelerating stage in this modified Einstein-de…

宇宙学与河外天体物理 · 物理学 2016-11-15 R. C. Santos , F. E. Silva , J. A. S. Lima

Weighted mean and median statistics techniques are used to combine 23 independent lower redshift, $z<1.04$, Hubble parameter, $H(z)$, measurements and determine binned forms of $H(z)$. When these are combined with 5 higher redshift,…

宇宙学与河外天体物理 · 物理学 2015-06-15 Omer Farooq , Sara Crandall , Bharat Ratra

In this article, we investigate the modified symmetric teleparallel gravity or $f(Q)$ gravity, where $Q$ is the non-metricity, to study the evolutionary history of the universe by considering the functional form of $f(Q)=\alpha Q^n$, where…

广义相对论与量子宇宙学 · 物理学 2022-12-16 Gaurav N. Gadbail , Sanjay Mandal , P. K. Sahoo

The cosmographic expansion history of the universe is investigated by using the 557 type Ia supernovae from the Union2 Compilation set along with the current estimates involving the product of the CMB acoustic scale $\ell_{A}$ and the BAO…

宇宙学与河外天体物理 · 物理学 2015-05-19 B. Santos , J. C. Carvalho , J. S. Alcaniz

In this work, we have considered a model independent approach to study the nature of the late time cosmic acceleration. We have used the Pade approximation to parametrize the comoving distance. Consequently, from this comoving distance, we…

宇宙学与河外天体物理 · 物理学 2020-01-09 Bikash R. Dinda

We study the late-time cosmology in $f(R, G)=R+\alpha R^{2}+\beta e^{\gamma G}$, using a logarithmic parametrization of the deceleration parameter $q(z)=q_{0}+q_{1}sin[log(1+z)]$. The Hubble parameter $H(z)$ is reconstructed and model…

广义相对论与量子宇宙学 · 物理学 2025-06-10 Amit Samaddar , S. Surendra Singh

In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters $H_0$ (Hubble constant) and $q$ (deceleration parameter). We investigate the constraints on these parameters using the…

广义相对论与量子宇宙学 · 物理学 2015-03-20 Sarita Rani , A. Altaibayeva , M. Shahalam , J. K. Singh , R. Myrzakulov

In this paper, we propose a simple parametrization of the Hubble parameter H in order to explain the late time cosmic acceleration. We show that our proposal covers many models obtained in different schemes of parametrization under one…

广义相对论与量子宇宙学 · 物理学 2022-07-20 S. K. J. Pacif , R. Myrzakulov , S. Myrzakul

We consider three `four-parameters' dark energy equations of state allowing fast transition from the matter dominated decelerating phase to the current accelerating phase. The fast-varying nature of the dark energy models is quantified by…

宇宙学与河外天体物理 · 物理学 2017-11-17 Rafael J. F. Marcondes , Supriya Pan

This article discusses a dark energy cosmological model in the standard theory of gravity - general relativity with a broad scalar field as a source. Exact solutions of Einstein's field equations are derived by considering a particular form…

广义相对论与量子宇宙学 · 物理学 2022-08-23 S. K. J. Pacif , Simran Arora , P. K. Sahoo

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…

宇宙学与河外天体物理 · 物理学 2022-05-31 Shulei Cao , Bharat Ratra

Using comoving distance $d_c$ and angular diameter distance $d_A$, we recalculate parameters describing kinematical state of the universe, still combining the kinematical model of universe but not relying on dynamical equations for gravity.…

宇宙学与河外天体物理 · 物理学 2021-05-27 Hai Huang , Long Huang