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In this work, FRW universe filled with dark matter (perfect fluid with negligible pressure) along with dark energy in the background of Galileon gravity is considered. Four dark energy models with different EoS parametrizations have been…

广义相对论与量子宇宙学 · 物理学 2015-09-09 Prabir Rudra , Chayan Ranjit , Sujata Kundu

Since the late 1990's observations of type Ia Supernova, our universe is predicted to experience a late time cosmic acceleration. Theoretical support to this observation were intended to be built via proposition of a hypothetical fluid…

广义相对论与量子宇宙学 · 物理学 2020-08-10 Promila Biswas , Parthajit Roy , Ritabrata Biswas

The behavior of the dark energy equation of state (EOS) is crucial in distinguishing different cosmological models. With a model independent approach, we constrain the possible evolution of the dark energy EOS. Gamma-ray bursts (GRBs) of…

天体物理学 · 物理学 2008-12-20 Shi Qi , Fa-Yin Wang , Tan Lu

In the framework of Brans-Dicke (BD) theory, the first part of the present study determines the time dependence of BD parameter, energy density and equation of state (EoS) parameter of the cosmic fluid in a universe expanding with…

广义相对论与量子宇宙学 · 物理学 2019-05-13 Sudipto Roy , Dipika Nandi , Sumana Ghosh , Apashanka Das

There are many kinds of models which describe the dynamics of dark energy (DE). Among all we adopt an equation of state (EoS) which varies as a function of time. We adopt Markov Chain Monte Carlo method to constrain the five parameters of…

宇宙学与河外天体物理 · 物理学 2016-11-15 R. Ichimasa , E. P. B. A. Thushari , M. Hashimoto

In this paper, the holographic dark energy in Brans-Dicke theory is confronted by cosmic observations from SN Ia, BAO and CMB shift parameter. The best fit parameters are found in $1\sigma$ region: $\Omega_{h0}=0.683^{+0.035}_{-0.038}$,…

宇宙学与河外天体物理 · 物理学 2009-05-27 Lixin Xu , Jianbo Lu , Wenbo Li

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

In this paper, we set the new limits on the equation of state parameter (EoS) of dark energy with the observations of cosmic microwave background radiation (CMB) from Planck satellite, the type Ia supernovae from Pan-STARRS and the baryon…

宇宙学与河外天体物理 · 物理学 2014-08-15 Wei Zheng , Si-Yu Li , Hong Li , Jun-Qing Xia , Mingzhe Li , Tan Lu

Soft cosmology is an extension of standard cosmology allowing for a scale-dependent equation-of-state (EoS) parameter in the dark sectors, which is one of the properties of soft materials in condensed-matter physics, that may arise either…

宇宙学与河外天体物理 · 物理学 2022-12-12 Emmanuel N. Saridakis , Weiqiang Yang , Supriya Pan , Fotios K. Anagnostopoulos , Spyros Basilakos

We consider a general dark energy (DE) model parametrized by its equation-of-state (EoS), featuring three free parameters: $w_0$ (the present-day value of the DE EoS), $w_{\beta}$ (quantifying the dynamical nature of the DE EoS), and…

宇宙学与河外天体物理 · 物理学 2026-03-24 Dong Ha Lee , Weiqiang Yang , Eleonora Di Valentino , Supriya Pan , Carsten van de Bruck

The Brans-Dicke (BD) theory is the simplest Scalar-Tensor theory of gravity, which can be considered as a candidate of modified Einstein's theory of general relativity. In this work, we forecast the constraints on BD theory in the CSST…

宇宙学与河外天体物理 · 物理学 2022-05-18 Anda Chen , Yan Gong , Fengquan Wu , Yougang Wang , Xuelei Chen

In this article, we investigate a new parametrization of the dark energy equation of state (EoS) with a single parameter for a barotropic fluid that deviates from the standard $\Lambda$CDM cosmology. We derive observational constraints on…

宇宙学与河外天体物理 · 物理学 2026-03-31 D. Revanth Kumar , Santosh Kumar Yadav

Determining the spatial curvature $\Omega_K$ of the Universe has long been crucial in cosmology. In practice, this effort is often entangled with assumptions of dark energy. A combination of distance ($D_{\rm M}$, $D_{\rm L}$) and expansion…

宇宙学与河外天体物理 · 物理学 2024-12-30 Zhennan Li , Pengjie Zhang

This paper constraints dynamic dark energy equation of state (EoS) parameters using the type Ia supernovae from Union 2.1 dataset. The paper also discusses the dependency of dynamic dark energy EoS parameters on the chosen or assumed value…

宇宙学与河外天体物理 · 物理学 2020-09-30 Syed Faisal ur Rahman

By using a Markov Chain Monte Carlo simulation, we investigate cosmological constraints on the ghost dark energy (GDE) model in the framework of the Brans-Dicke (BD) theory. A combination of the latest observational data of the cosmic…

宇宙学与河外天体物理 · 物理学 2014-06-13 Hamzeh Alavirad , Ahmad Sheykhi

We study a correspondence between $f(R)$ model of gravity and a phenomenological kind of dark energy (DE), which is known as QCD ghost dark energy. Since this kind of dark energy is not stable in the context of Einsteinian theory of gravity…

综合物理 · 物理学 2014-01-21 Kh. Saaidi , Ali. Aghamohammadi , B. Sabet , O. Farooq

In this paper first we study Brans-Dicke equations with the cosmological constant to find an exact solution in the spatially flat Robertson-Walker metric. Then we use Observational Hubble data, the baryon acoustic oscillation distance ratio…

广义相对论与量子宇宙学 · 物理学 2020-08-26 Hassan Amirhashchi , Anil Kumar Yadav

Three general cases of dynamical interacting dark energy models ($\mathcal{D}$-class) are investigated in the context of Brans-Dicke cosmology. Some of important cosmological quantities are calculated for every cases as a function of…

宇宙学与河外天体物理 · 物理学 2019-11-28 E. Karimkhani , A. Khodam-Mohammadi

We use the newly released 182 Type Ia supernova data combined with the third-year Wilkinson Microwave Anisotropic Probe data (WMAP3) and large scale structure (LSS) information including SDSS and 2dFGRS to constrain the dark energy equation…

天体物理学 · 物理学 2008-11-26 Gong-Bo Zhao , Jun-Qing Xia , Hong Li , Charling Tao , Jean-Marc Virey , Zong-Hong Zhu , Xinmin Zhang

Using the covariant formalism developed in a companion paper (paper I), we derive observational constraint on the Brans-Dicke model in a flat FLRW universe with cosmological constant and cold dark matter. The CMB observations we use include…

宇宙学与河外天体物理 · 物理学 2014-11-18 Fengquan Wu , Xuelei Chen
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