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Related papers: Twinlike models for parametrized dark energy

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A comparative study of various parametrizations of the dark energy equation of state $w(z)$ and its variation with the redshift is made. Astrophysical constraints from 'integrated tracking' are laid down to test the physical viability and…

Astrophysics · Physics 2007-05-23 Vinod B. Johri

We investigate an interacting two-fluid cosmological model and introduce a scalar field representation by means of a linear combination of the individual energy densities. Applying the integrability condition to the scalar field equation we…

Astrophysics · Physics 2008-11-26 Luis Chimento , Monica Forte

Einstein field equations under spherically symmetric space-times are considered here in connection to dark energy investigation. A set of solutions are obtained for a kinematical $\Lambda$ model, viz., $\Lambda \sim (\dot a/a)^2$ without…

General Relativity and Quantum Cosmology · Physics 2009-05-12 Utpal Mukhopadhyay , P. C. Ray , Saibal Ray , S. B. Datta Choudhury

While modelling our late time cosmically accelerated universe, it is popular to involve different dark energy models, the equation of state of which can be taken as a function of the redshift and some unknown parameters. Barboza and Alcaniz…

General Physics · Physics 2019-09-25 Swetalina Bhowmik , Ritabrata Biswas

As an alternative to the popular parametrisations of the dark energy equation of state, we construct a quintessence model where the scalar field has a linear dependence on the number of e-folds. Constraints on more complex models are…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-17 Vitor da Fonseca , Tiago Barreiro , Nelson J. Nunes

A general equation of state is considered for analysing the possible behaviors for (Early) dark energy that alleviates the Hubble parameter tension problem. By departing from the possible evolution for the (Early) dark energy density and…

General Relativity and Quantum Cosmology · Physics 2021-05-25 Shin'ichi Nojiri , Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

One of the main challenges of modern cosmology is to investigate the nature of dark energy in our Universe. The properties of such a component are normally summarised as a perfect fluid with a (potentially) time-dependent equation-of-state…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-19 J. Alberto Vazquez , M. Bridges , M. P. Hobson , A. N. Lasenby

A review on spatially flat D-dimensional Friedmann-Robertson-Walker (FRW) model of the universe has been performed. Some standard parameterizations of the equation of state parameter of the Dark Energy models are proposed and the…

General Relativity and Quantum Cosmology · Physics 2019-03-26 Tanwi Bandyopadhyay , Ujjal Debnath

In this work we determine the correspondence between quintessence and tachyon dark energy models with a constant dark energy equation of state parameter, $w_e$. Although the evolution of both the Hubble parameter and the scalar field…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 P. P. Avelino , L. Losano , J. J. Rodrigues

A simple speed-up cosmology model is proposed to account for the dark energy puzzle. We condense contributions from dark energy and curvature term into one effective parameter in order to reduce parameter degeneracies and to find any…

Astrophysics · Physics 2007-10-10 Xin-He Meng , Meng Su , Zheng Wang

We present a conjugate analysis of two different dark energy models investigating both their agreement with recent data and their thermodynamical properties. The successful match with the data allows to both constrain the model parameters…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-11 Vincenzo F. Cardone , Ninfa Radicella , Antonio Troisi

Evolution of the universe with modified holographic Ricci dark energy model is considered. Dependency of the equation of state parameter and deceleration parameter on the redshift and model parameters are obtained. It is shown that the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-13 Titus K Mathew , Jishnu Suresh , Divya Divakaran

Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology…

Astrophysics · Physics 2009-07-09 E. M. Barboza , J. S. Alcaniz

In this paper we investigate a new phenomenological parameterization for unified dark matter and dark energy based on the polynomial expansion of the barotropic equation of state parameter $w$. Our parameterization provides well-behaving…

General Relativity and Quantum Cosmology · Physics 2018-08-01 Zahra Davari , Mohammad Malekjani , Michal Artymowski

We explore freezing dark energy, where the evolution of the field approaches that of a cosmological constant at late times. We propose two general, two parameter forms to describe the class of freezing field models, in analogy to ones for…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Eric V. Linder

We investigate the effects of viscosity terms depending on the Hubble parameter and its derivatives in the dark energy equation of state. Such terms are possible if dark energy is a fictitious fluid originating from corrections to the…

Astrophysics · Physics 2010-04-06 S. Capozziello , V. F. Cardone , E. Elizalde , S. Nojiri , S. D. Odintsov

The current accelerating phase of the evolution of the universe is considered by constructing most economical cosmic models that use just general relativity and some dominating quantum effects associated with the probabilistic description…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Pedro F. González-Díaz , Alberto Rozas-Fernández

Twinlike defects refer to topological defect solutions of some apparently different field models that share the same defect configuration and the same energy density. Usually, one can distinguish twinlike defects in terms of their linear…

High Energy Physics - Theory · Physics 2015-10-27 Yuan Zhong , Yu-Xiao Liu

Three models of a flat universe of coupled matter and dark energies with different low-redshift parameterizations of the dark energy equation of state are considered. The dark energy is assumed to vary with time like the trace of the…

Astrophysics · Physics 2011-08-04 A. -M. M. Abdel-Rahman , Ihab F. Riad

We revisit the theoretical priors used for inferring Dark Energy (DE) parameters. Any DE model must have some form of a tracker mechanism such that it behaved as matter or radiation in the past. Otherwise, the model is fine-tuned. We…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-24 Ido Ben-Dayan , Utkarsh Kumar