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Related papers: Generalized ghost dark energy in Brans-Dicke theor…

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We discuss the cosmological consequences of a model based on a non-local infrared modification of Einstein equations. We find that the model generates a dynamical dark energy that can account for the presently observed value of $\Omega_{\rm…

High Energy Physics - Theory · Physics 2015-06-16 Michele Maggiore

We investigate the ghost model of dark energy in the framework of DGP braneworld. We explore the cosmological consequences of this model by determining the equation of state parameter, $\omega_D$, the deceleration and the density…

General Relativity and Quantum Cosmology · Physics 2018-10-31 M. Abdollahi Zadeh , A. Sheykhi

Using the Tsallis generalized entropy, holographic hypothesis and also considering the Hubble horizon as the IR cutoff, we build a holographic model for dark energy and study its cosmological consequences in the Brans-Dicke framework. At…

General Relativity and Quantum Cosmology · Physics 2018-09-05 S. Ghaffari , H. Moradpour , I. P. Lobo , J. P. Morais Graça , Valdir B. Bezerra

In this paper, we point out thermodynamical description of ghost dark energy and its generalization to the early universe. Thereinafter, we find expressions for the entropy changes of these dark energy candidates. In addition, considering…

General Relativity and Quantum Cosmology · Physics 2015-05-06 M. Honarvaryan , A. Sheykhi , H. Moradpour

In this paper, we investigate the cosmological consequences of ghost dark energy model in modified Gauss-Bonnet gravity. We construct ghost dark energy $f(G)$ model by using correspondence scenario for both interacting and non-interacting…

General Relativity and Quantum Cosmology · Physics 2019-08-21 M. Sharif , Saadia Saba

We study observational consequences of the model for dark energy proposed in [1] (Aoki et al., Phys.Rev. D97 (2018) no.4, 043517). We assume our universe has been created by bubble nucleation, and consider quantum fluctuations of an…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Daisuke Yamauchi , Hajime Aoki , Satoshi Iso , Da-Shin Lee , Yasuhiro Sekino , Chen-Pin Yeh

I consider some of the issues we face in trying to understand dark energy. Huge fluctuations in the unknown dark energy equation of state can be hidden in distance data, so I argue that model-independent tests which signal if the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Chris Clarkson

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

The phenomenon of the dark energy transition between the quintessence regime ($w > -1$) and the phantom regime ($w < -1$), also known as the cosmological constant boundary crossing, is analyzed in terms of the dark energy equation of state.…

Astrophysics · Physics 2009-11-13 Hrvoje Stefancic

Stability analysis of agegraphic dark energy in Brans-Dicke theory is presented in this paper. We constrain the model parameters with the observational data and thus the results become broadly consistent with those expected from experiment.…

General Physics · Physics 2015-06-03 H. Farajollahi , J. Sadeghi , M. Pourali , A. Salehi

We formulate power-law holographic dark energy, which is a modified holographic dark energy model based on the extended entropy relation arising from the consideration of state mixing between the ground and the excited ones in the…

General Relativity and Quantum Cosmology · Physics 2022-05-25 Eirini C. Telali , Emmanuel N. Saridakis

We here investigate the model of interacting dark energy in the context of five dimensional brane cosmology. The effective equations of state of dark energy are evaluated for various choices of the variable time dependent cosmological…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Mubasher Jamil

In the 5-year WMAP data analysis, a new parametrization form for dark energy equation-of-state was used, and it has been shown that the equation-of-state, $w(z)$, crosses the cosmological-constant boundary $w=-1$. Based on this observation,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jingfei Zhang , Yuan-Xing Gui

We reconsider the holographic dark energy (HDE) model with a slowly time varying $ c^2(z)$ parameter in the energy density, namely $\rho_D=3M_p^2 c^2(z)/L^2$, where $L$ is the IR cutoff and $z$ is the redshift parameter. As the system's IR…

General Physics · Physics 2017-06-06 A. Sheykhi , S. Ghaffari , N. Roshanshah

We suggest that the solution to the cosmological vacuum energy puzzle is linked to the infrared sector of the effective theory of gravity interacting with standard model fields, with QCD fields specifically. We work in the framework of low…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Federico R. Urban , Ariel R. Zhitnitsky

We perform a study of cosmic evolution with an equation of state parameter $\omega(t)=\omega_0+\omega_1(t\dot H/H)$ by selecting a phenomenological $\Lambda$ model of the form, $\dot\Lambda\sim H^3$. This simple proposition explains both…

General Relativity and Quantum Cosmology · Physics 2009-11-13 A. A. Usmani , P. P. Ghosh , Utpal Mukhopadhyay , P. C. Ray , Saibal Ray

We explore the properties of dark energy models for which the equation-of-state, w, defined as the ratio of pressure to energy density, crosses the cosmological-constant boundary w = -1. We adopt an empirical approach, treating the dark…

Astrophysics · Physics 2010-04-06 Robert R. Caldwell , Michael Doran

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

In Brans-Dicke theory a non-linear self interaction of a scalar field allows a possibility of realizing the late-time cosmic acceleration, while recovering the General Relativistic behavior at early cosmological epochs. We extend this to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Antonio De Felice , Shinji Tsujikawa

We consider the holographic dark energy (HDE) model in the framework of DGP braneworld with Granda-Oliveros infrared (IR) cutoff, $L=(\alpha \dot{H}+\beta H^2)^{-1/2}$. With this choice for IR cutoff, we are able to derive evolution of the…

General Relativity and Quantum Cosmology · Physics 2015-06-05 S. Ghaffari , M. H. Dehghani , A. Sheykhi
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