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We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the X-ray gas mass fraction in cluster and the Hubble…

Astrophysics · Physics 2008-11-26 Puxun Wu , Hongwei Yu

We investigate the dark energy phenomenology in an extended parameter space where we allow the curvature density of our universe as a free-to-vary parameter. The inclusion of the curvature density parameter is motivated from the recently…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-29 Mehdi Rezaei , Supriya Pan , Weiqiang Yang , David F. Mota

It has been shown that the new Self Creation Cosmology theory predicts a universe with a total density parameter of one third yet spatially flat, which would appear to accelerate in its expansion. Although requiring a moderate amount of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Garth A Barber

It has been found in previous studies that, for the Supernova Legacy Survey three-year (SNLS3) data, there is strong evidence for the redshift-evolution of color-luminosity parameter $\beta$. In this paper, using three simplest dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-25 Shuang Wang , Yun-He Li , Xin Zhang

In this study, we investigate the $w$CDM dynamical dark energy model with spatial curvature utilizing the recently released DESI Collaboration data (DR1 and DR2) in conjunction with other observational probes such as BBN, Observational…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 Manish Yadav , Archana Dixit , M. S. Barak , Anirudh Pradhan

We use the Simon, Verde, & Jimenez (2005) determination of the redshift dependence of the Hubble parameter to constrain cosmological parameters in three dark energy cosmological models. We consider the standard $\Lambda$CDM model, the XCDM…

Astrophysics · Physics 2011-02-11 Lado Samushia , Bharat Ratra

We investigate the QCD ghost model of dark energy in the framework of Brans-Dicke cosmology. First, we study the non-interacting ghost dark energy in a flat Brans-Dicke theory. In this case we obtain the EoS and the deceleration parameters…

High Energy Physics - Theory · Physics 2015-05-28 Esmaeil Ebrahimi , Ahmad Sheykhi

So far large and different data sets revealed the accelerated expansion rate of the Universe, which is usually explained in terms of dark energy. The nature of dark energy is not yet known, and several models have been introduced: a non…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-16 M. Demianski , E. Piedipalumbo , D. Sawant , L. Amati

The pure Brans-Dicke (BD) gravity with or without the cosmological constant $\Lambda $ has been taken as a model theory for the dark matter. Indeed, there has been a consensus that unless one modifies either the standard theory of gravity,…

Astrophysics · Physics 2007-08-21 Hongsu Kim

FRW universe in RS II braneworld model filled with a combination of dark matter and dark energy in the form of modified Chaplygin gas (MCG) is considered. It is known that the equation of state (EoS) for MCG is a three-variable equation…

General Physics · Physics 2015-06-15 Chayan Ranjit , Prabir Rudra , Sujata Kundu

Perhaps the most explored hypothesis for the accelerated cosmic expansion rate arises in the context of extra fields or modifications to General Relativity. A prevalent approach is to parameterize the expansion history through the equation…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-14 Mariana Jaber , Gustavo Arciniega , Luisa G. Jaime , Omar A. Rodríguez-López

In order to explain the current acceleration of the Universe, the fine tuning problem of the cosmological constant $\Lambda$ and the cosmic coincidence problem, different alternative models have been proposed in the literature. We use the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-13 Alexander Bonilla Rivera , Jorge García Farieta

We constrain two non-flat time-evolving dark energy cosmological models by using Hubble parameter data, Type Ia supernova apparent magnitude measurements, and baryonic acoustic oscillation peak length scale observations. The inclusion of…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Omer Farooq , Data Mania , Bharat Ratra

We reconstruct evolution of the dark energy (DE) density using a nonparametric Bayesian approach from a combination of latest observational data. We caution against parameterizing DE in terms of its equation of state as it can be singular…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Yuting Wang , Levon Pogosian , Gong-Bo Zhao , Alex Zucca

We propose a phenomenological unified model for dark matter and dark energy based on an equation of state parameter $w$ that scales with the $\arctan$ of the redshift. The free parameters of the model are three constants: $\Omega_{b0}$,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-17 R. R. Cuzinatto , L. G. Medeiros , E. M. de Morais

We report strong cosmological constraints on the Brans-Dicke (BD) theory of gravity using Cosmic Microwave Background data from Planck.We consider two types of models. First, the initial condition of the scalar field is fixed to give the…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-09 A. Avilez , C. Skordis

We reconstruct the Equation of State of Dark Energy (EoS) from current data using a non-parametric approach where, rather than assuming a specific time evolution of this function, we bin it in time. We treat the transition between the bins…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-23 Francesca Gerardi , Matteo Martinelli , Alessandra Silvestri

Although $\Lambda$CDM model is very successful in many aspects, it has been seriously challenged. Recently, warm dark matter (WDM) remarkably rose as an alternative of cold dark matter (CDM). In the literature, many attempts have been made…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Hao Wei , Zu-Cheng Chen , Jing Liu

A new bound dark energy, BDE, cosmology has been proposed where the dark energy is the binding energy between light meson fields that condense a few tens of years after the big bang. It is reported that the correct dark energy density…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Rodger I. Thompson

In this work, we have considered the flat FRW model of the universe in $(n+2)$-dimensions filled with the dark matter and the magnetic field. We present the Hubble parameter in terms of the observable parameters $\Omega_{m0}$ and $H_{0}$…

General Physics · Physics 2013-04-05 Chayan Ranjit , Shuvendu Chakraborty , Ujjal Debnath