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Related papers: Instability of holographic dark energy models

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In dark energy models of scalar-field coupled to a barotropic perfect fluid, the existence of cosmological scaling solutions restricts the Lagrangian of the field $\vp$ to $p=X g(Xe^{\lambda \vp})$, where $X=-g^{\mu\nu} \partial_\mu \vp…

High Energy Physics - Theory · Physics 2009-02-25 Burin Gumjudpai , Tapan Naskar , M. Sami , Shinji Tsujikawa

Vacuum energy is a simple model for dark energy driving an accelerated expansion of the universe. If the vacuum energy is inhomogeneous in spacetime then it must be interacting. We present the general equations for a spacetime-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-01 Josue De-Santiago , David Wands , Yuting Wang

We explore the possibility that the dark matter and dark energy are mimicked by a single fluid or by a single $k$-essence-like scalar field. The so called Chaplygin gas unified dark matter models can reproduce the observed matter power…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-28 Yuko Urakawa , Tsutomu Kobayashi

In this paper we study the interaction between the general form of viscous varying modified cosmic Chaplygin gas and the Tachyon fluid in the framework of Einstein gravity. We want to reconstruct the Tachyon potential and total equation of…

General Relativity and Quantum Cosmology · Physics 2013-08-05 Jafar Sadeghi , Hoda Farahani

The paper deals with a dynamical system analysis of the cosmological evolution of an holographic dark energy (HDE) model interacting with dark matter (DM) which is chosen in the form of dust. The infrared cut-off of the holographic model is…

General Relativity and Quantum Cosmology · Physics 2015-11-26 Nilanjana Mahata , Subenoy Chakraborty

In this paper, we have considered that the universe is filled with tachyon, hessence (or hantom) dark energies. Subsequently we have investigated the interactions between tachyon and hessence (hantom) dark energies and calculated the…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Surajit Chattopadhyay , Ujjal Debnath

In this letter we consider two different models of our present universe. We choose the models which are consisting different sets of two seperate fluids. The first one of each set tries to justify the late time acceleration and the second…

General Physics · Physics 2019-03-27 Promila Biswas , Ritabrata Biswas

Unified dark matter models are appealing in that they describe the dark sector in terms of a single component. They however face problems when attempting to account for structure formation: in the linear regime, density fluctuations can…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Amr El-Zant

We establish a connection between the agegraphic models of dark energy and Chaplygin gas energy density in non-flat universe. We reconstruct the potential of the agegraphic scalar field as well as the dynamics of the scalar field according…

High Energy Physics - Theory · Physics 2010-02-18 Ahmad Sheykhi

We suggest a perturbative approach for generic choices for the universe equation of state and introduce a novel framework for studying mass varying neutrinos (MaVaN's) coupled to the dark sector. For concreteness, we examine the coupling…

Astrophysics · Physics 2010-01-16 Alex E. Bernardini , O. Bertolami

Combining the general relativity and the uncertainty relation in quantum mechanics, the energy density of quantum fluctuations of space-time can be viewed as dark energy. The so-called agegraphic dark energy model is just based on this…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Jinglei Cui , Li Zhang , Jingfei Zhang , Xin Zhang

In this paper we consider a correspondence between the holographic dark energy density and interacting generalized Chaplygin gas energy density in FRW universe. Then we reconstruct the potential of the scalar field which describe the…

High Energy Physics - Theory · Physics 2008-11-26 M. R. Setare

We explore the fate of the universe given the possibility that the density associated with `dark energy' may decay slowly with time. Decaying dark energy is modeled by a homogeneous scalar field which couples minimally to gravity and whose…

Astrophysics · Physics 2009-11-07 Ujjaini Alam , Varun Sahni , A. A. Starobinsky

The mass power spectrum for a Universe dominated by the Chaplygin gas is evaluated numerically from scales of the order of the Hubble horizon to 100 Mpc. The results are compared with a pure baryonic Universe and a cosmological constant…

Astrophysics · Physics 2016-08-16 J. C. Fabris , S. V. B. Gonçalves , P. E. de Souza

Interesting discrepancies in cosmological parameters are challenging the success of the $\Lambda$CDM model. Direct measurements of the Hubble constant $H_0$ using Cepheid variables and supernovae turn out to be higher than inferred from the…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-23 Wilmar Cardona , M. A. Sabogal

The holographic dark energy (HDE) is considered to be the most promising candidate of dark energy. Its definition is originally motivated from the entropy-area relation which depends on the theory of gravity under consideration. Recently a…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Mubasher Jamil , M. Umar Farooq

This paper focuses on developing a generalized ghost dark energy model $f\mathcal{(Q,T)}$ through the correspondence scheme for a non-interacting scenario involving pressureless matter and a power-law scale factor. We analyze the…

General Relativity and Quantum Cosmology · Physics 2024-09-06 M. Sharif , Iqra Ibrar

We investigate the Tsallis holographic dark energy (THDE) models in the context of perturbations' growth. We assume the description of dark energy by considering the holographic principle and the nonadditive entropy to carry out this. We…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-21 W. J. C. da Silva , R. Silva

We make a comparison for ten typical, popular dark energy models according to their capabilities of fitting the current observational data. The observational data we use in this work include the JLA sample of type Ia supernovae observation,…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-08 Yue-Yao Xu , Xin Zhang

Dark energy is now one of the most important and topical problems in cosmology. The first step to reveal its nature is to detect the evolution of dark energy or to prove beyond doubt that the cosmological constant is indeed constant.…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-21 Krzysztof Bolejko