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Bulk dark energy properties are determined by the redshift evolution of its pressure-to-density ratio, $w_{de}(z)$. An experimental goal is to decide if the dark energy is dynamical, as in the quintessence (and phantom) models treated here.…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Zhiqi Huang , J. Richard Bond , Lev Kofman

In this paper, we present an analytical solution for the interacting generalized holographic dark energy model, assuming a linear interaction rate between dark energy and dark matter. We determine the equation of state parameter, the…

General Relativity and Quantum Cosmology · Physics 2024-10-15 Omar Enkhili , Farida Bargach , Dalale Mhamdi , Taoufik Ouali , Ahmed Errahmani

We introduce a new parametrization for the dark energy, led by the same idea to the linear expansion of the equation of state in scale factor $a$ and in redshift $z$, which diverges neither in the past nor future and contains the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Ozgur Akarsu , Tekin Dereli , J. Alberto Vazquez

We investigate the cosmological implications of a generalized total equation of state (EoS) model by constraining its parameters using observational datasets to effectively characterize the universe's expansion history and its dynamic…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 M. Koussour , S. Bekov , A. Syzdykova , S. Muminov , I. Ibragimov , J. Rayimbaev

In this paper we consider several phenomenological models of variable $\Lambda$. Model of a flat Universe with variable $\Lambda$ and $G$ is accepted. It is well known, that varying $G$ and $\Lambda$ gives rise to modified field equations…

General Relativity and Quantum Cosmology · Physics 2013-12-17 J. Sadeghi , M. Khurshudyan , A. Movsisyan , H. Farahani

In this paper we analyze the constraints on the property of dark energy from cosmological observations. Together with SNe Ia Gold sample, WMAP, SDSS and 2dFGRS data, we include 69 long Gamma-Ray Bursts (GRBs) data in our study and perform…

Astrophysics · Physics 2008-11-26 Hong Li , Meng Su , Zuhui Fan , Zigao Dai , Xinmin Zhang

We explore the cosmological implications of the interactions among the dark particles in the dark $SU(2)_R$ model. It turns out that the relevant interaction is between dark energy and dark matter, through a decay process. With respect to…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-02 Ricardo G. Landim , Rafael J. F. Marcondes , Fabrízio F. Bernardi , Elcio Abdalla

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

The some models of holographic dark energy for Randall-Sandrum brane are considered. For first class of dark energy models we take energy density in form $\sim L^{2\gamma-4}$ where $L$ is size of events horizon in Universe and $\gamma$ is…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Artyom V. Astashenok , Alexander S. Tepliakov

We consider a model-independent approach to constrain the equivalence redshift, $z_{eq}$, at which dark energy and the total matter (cold dark matter and baryonic) equate their magnitudes. To this aim, in the context of a homogeneous and…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-31 Anna Chiara Alfano , Carlo Cafaro , Salvatore Capozziello , Orlando Luongo

The paper explores the interacting Tsallis holographic dark energy (THDE) model in a non-flat universe following an infrared cutoff as the apparent horizon. The equation of state (EoS) and the deceleration parameter of THDE model are…

General Physics · Physics 2021-08-02 Umesh Kumar Sharma , Vipin Chandra Dubey , A. Pradhan

We have analyzed the Barrow holographic dark energy (BHDE) in the framework of the flat FLRW Universe by considering the various estimations of Barrow exponent $\triangle$. Here we define BHDE, by applying the usual holographic principle at…

General Relativity and Quantum Cosmology · Physics 2021-08-02 Anirudh Pradhan , Archana Dixit , Vinod Kumar Bhardwaj

In this paper, we have studied flat Friedmann--Lema\^{\i}tre--Robertson--Walker (FLRW) model with modified Chaplygin gas (MCG) having equation of state $p_{m}=A\rho -% \frac{B}{\rho ^{\gamma }}$, where $0\leq A\leq 1$, $0\leq \gamma \leq 1$…

General Relativity and Quantum Cosmology · Physics 2022-07-20 J. K. Singh , Ritika Nagpal , S. K. J. Pacif

Observational evidence for the existence of dark energy is strong. Here we suggest a model which is based on a modified gravitational theory in 5D and interpret the 5th dimension as a manifestation of dark energy in the 4D observable…

High Energy Physics - Theory · Physics 2008-01-22 H. Alavirad , N. Riazi

We study the utility of wavelets for detecting the redshift evolution of the dark energy equation of state w(z) from the combination of supernovae, CMB and BAO data. We show that local features in w, such as bumps, can be detected…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-20 Alireza Hojjati , Levon Pogosian , Gong-Bo Zhao

We examine several dark energy models with a time-varying equation of state parameter, $w(z)$, to determine what information can be derived by fitting the distance modulus in such models to a constant equation of state parameter, $w_*$. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-21 Samuel S. Taylor , Robert J. Scherrer

We investigate the dynamical properties of dark energy through a detailed analysis of its equation of state parameter $w(z)$ as a function of redshift. We derive a general expression for $w(z)$ from the Friedmann-Lema\^itre-Robertson-Walker…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-29 J. W. Moffat , E. J. Thompson

We obtain a class of solutions for the AdS$_5$ two-brane models by imposing the observed value of cosmological constant and Newton coupling constant on the visible brane. When all terms up to the first order of matter density are included,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Houri Ziaeepour

In this work we explore a Holographic Dark Energy Model in a flat Friedmann-Lema\^itre-Robertson-Walker Universe, which contains baryons, radiation, cold dark matter and dark energy within the framework of General Relativity. Furthermore,…

General Relativity and Quantum Cosmology · Physics 2019-05-10 Carlos Rodriguez-Benites , Mauricio Cataldo , Antonella Cid , Carlos Ríos

Current universe (assumed here to be normal matter on the brane) is pressureless from observations. In this case the energy condition is $\rho_0\geq0$ and $p_0=0$. By using this condition, brane models can be distinguished. Then, assuming…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Yongli Ping , Lixin Xu , Baorong Chang , Hongya Liu
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