English
Related papers

Related papers: Statefinder parameters in two dark energy models

200 papers

In this paper, we explore various cosmological parameters and cosmological planes ($\omega_D-{\omega_D}^{\prime}$, statefinder) for new Tsallis agegraphic dark energy in the framework of Chern-Simons modified gravity. We consider this…

General Physics · Physics 2020-01-23 M. Abdollahi Zadeh

Equation of state parameter plays a significant role for guessing the real nature of dark energy. In the present paper polytropic equation of state $p=\omega\rho^n$ is chosen for some of the kinematical $\Lambda$-models viz., $\Lambda \sim…

Astrophysics · Physics 2009-02-11 Utpal Mukhopadhyay , Saibal Ray

Are geometrical summaries of the CMB and LSS sufficient for estimating cosmological parameters? And how does our choice of a dark energy model impact the current constraints on standard cosmological parameters? We address these questions in…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-17 Rahul Biswas , Benjamin D. Wandelt

A comparative study of various parametrizations of the dark energy equation of state is made. Astrophysical constraints from LSS, CMB and BBN are laid down to test the physical viability and cosmological compatibility of these…

Astrophysics · Physics 2008-11-26 Vinod B. Johri , P. K. Rath

The dynamical behaviors of two interacting dark energy models are considered. In addition to the scaling attractors found in the non-interacting quintessence model with exponential potential, new accelerated scaling attractors are also…

General Relativity and Quantum Cosmology · Physics 2011-03-28 Xi-ming Chen , Yungui Gong

In this work, we have considered that the flat FRW universe is filled with the mixture of dark matter and the new holographic dark energy. If there is an interaction, we have investigated the natures of deceleration parameter, statefinder…

General Physics · Physics 2015-05-27 Ujjal Debnath , Surajit Chattopadhyay

We constrain the parameters of dynamical dark energy in the form of a classical scalar field with barotropic equation of state jointly with other cosmological parameters using various combined datasets including the CMB power spectra from…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Olga Sergijenko , Bohdan Novosyadlyj

We consider interacting dark matter-dark energy models arising out of a general interaction term $Q=f(\rho_{m},\rho_{d},\dot{\rho}_{m},\dot{\rho}_{d}).$ Here $f$ is a functional relation connecting the energy densities $\rho_{m}$ and…

General Relativity and Quantum Cosmology · Physics 2024-05-24 Subhra Bhattacharya

In this paper, we apply the statefinder diagnostic to the cosmology with the Abnormally Weighting Energy hypothesis (AWE cosmology), in which dark energy in the observational (ordinary matter) frame results from the violation of weak…

Astrophysics · Physics 2008-12-18 Dao-Jun Liu , Wei-Zhong Liu

We investigate cosmological models with two interacting fluids: dark energy and dark matter in flat Friedmann-Robertson-Walker universe. The interaction between dark energy and dark matter is described in terms of the parameters present in…

General Relativity and Quantum Cosmology · Physics 2015-02-23 I. Brevik , V. V. Obukhov , A. V. Timoshkin

We propose a new cosmological model that considers dark matter as a barotropic fluid with a constant equation of state parameter and interprets dark energy as the phenomenological emergent dark energy rather than a cosmological constant.…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Jianqi Liu , Yanhong Yao , Yan Su , Junchao Wang , Jiawei Wu

In this paper, we study a model which is composed by the cosmological constant and dark matter with nonzero equation of state parameter, which could be called as $\Lambda$wDM. In the synchronous gauge, we obtain the perturbation equations…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-01 Weiqiang Yang , Lixin Xu

Equations of State model relations between thermodynamic variables and are ubiquitous in scientific modelling, appearing in modern day applications ranging from Astrophysics to Climate Science. The three desired properties of a general…

Nearly all proposed tests for the nature of dark energy measure some combination of four fundamental observables: the Hubble parameter H(z), the distance-redshift relation d(z), the age-redshift relation t(z), or the linear growth factor…

Astrophysics · Physics 2009-11-13 David H. Weinberg

A new dark energy model, named as ``agegraphic dark energy'', has been proposed by one of us (R. G. Cai) in arXiv:0707.4049, based on the K\'{a}rolyh\'{a}zy uncertainty relation, which arises from the quantum mechanics together with general…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hao Wei , Rong-Gen Cai

We study the evolution of the dark energy parameter within the scope of a spatially non-flat and isotropic Friedmann-Robertson-Walker (FRW) model filled with barotropic fluid and bulk viscous stresses. We have obtained cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Hassan Amirhashchi , Anirudh Pradhan , Hishamuddin Zainuddin

We investigate interacting ghost dark energy models in higher dimensional cosmology. We attempt to model dark matter within a barotropic fluid with $P_{b}=\omega(t)_{b}\rho$. In this work we consider four different models based on choosing…

General Relativity and Quantum Cosmology · Physics 2016-05-25 J. Sadeghi , M. Khurshudyan , H. Farahani

In this paper, we propose a general form of the equation of state (EoS) which is the function of the fractional dark energy density $\Omega_{d}$. At least, five related models, the cosmological constant model, the holographic dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Yi Zhang , Hui Li

Dark energy and dark matter are only indirectly measured via their gravitational effects. It is possible that there is an exchange of energy within the dark sector, and this offers an interesting alternative approach to the coincidence…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Gabriela Caldera-Cabral , Roy Maartens , L. Arturo Urena-Lopez

We investigate a kind of holographic dark energy model with the future event horizon the IR cutoff and the equation of state -1. In this model, the constraint on the equation of state automatically specifies an interaction between matter…

Astrophysics · Physics 2007-05-23 Hui Li , Zong-kuan Guo , Yuan-zhong Zhang