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Braneworld models of dark energy are examined in the light of observations of high redshift type Ia supernovae. Braneworld models admit several novel and even exotic possibilities which include: (i) The effective equation of state of dark…

Astrophysics · Physics 2007-05-23 Ujjaini Alam , Varun Sahni

We propose a Friedmann-Lemaitre-Robertson-Walker cosmological model with a scalar field that represents dark energy. A new parametrization of the deceleration parameter is introduced of the form $q = 1 + \eta (1 + \mu a^{\eta})$ where…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-07 Aroonkumar Beesham

This paper investigates the flat Friedmann-Lema$\hat{\imath}$tre-Robertson-Walker (FLRW) cosmological model using a suitable parameterization represented as a differential equation concerning the energy density of the scalar field,…

General Relativity and Quantum Cosmology · Physics 2024-04-30 J. K. Singh , Shaily , Harshna Balhara , Sushant G. Ghosh , Sunil D. Maharaj

In this work, we assume the FRLW Universe which is filled with dark matter along with dark energy in the framework of Horava-Lifshitz (HL) gravity. The dark energy is considered as the Linear (Model I) and CPL (Model II) parametrizations of…

General Relativity and Quantum Cosmology · Physics 2024-02-07 Himanshu Chaudhary , Niyaz Uddin Molla , Madhur Khurana , Ujjal Debnath , G. Mustafa

The inflationary epoch and the late time acceleration of the expansion rate of universe can be explained by assuming a gravitationally coupled scalar field. In this article, we propose a new method of finding exact solutions in the…

General Relativity and Quantum Cosmology · Physics 2022-09-19 Albin Joseph , Rajib Saha

We discuss dark energy models which might describe effectively the actual acceleration of the universe. More precisely, for a 4-dimensional Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) universe we consider two situations: First of them,…

Astrophysics · Physics 2008-11-26 Mariam Bouhmadi-Lopez , Jose A. Jimenez Madrid

We consider ideal fluid and equivalent scalar field dark energy universes where all four known types of finite-time, future singularities occur at some parameter values. It is demonstrated that pressure/energy density of such…

High Energy Physics - Theory · Physics 2015-05-13 Shin'ichi Nojiri , Sergei D. Odintsov

We consider FLRW cosmological models with standard Friedmann equations, but leaving free the equation of state. We assume that the dark energy content of the universe is encoded in an equation of state $p=f(\rho)$, which is expressed with…

General Relativity and Quantum Cosmology · Physics 2014-11-20 L. Fernandez-Jambrina , R. Lazkoz

We study cosmological models involving a single real scalar field that has an equation of state parameter which evolves with cosmic time. We highlight some common parametrizations for the equation of state as a function of redshift in the…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-26 J. D. Dantas , J. J. Rodrigues

Properties of Braneworld models of dark energy are reviewed. Braneworld models admit the following interesting possibilities: (i) The effective equation of state can be w < -1 as well as w > -1. In the former case the expansion of the…

Astrophysics · Physics 2007-05-23 Varun Sahni

In this paper, we have presented a model of the FLRW universe filled with matter and dark energy fluids, by assuming an ansatz that deceleration parameter is a linear function of the Hubble constant. This results in a time-dependent DP…

General Relativity and Quantum Cosmology · Physics 2021-08-02 Gopi Kant Goswami , Anirudh Pradhan , Aroonkumar Beesham

We revisit the evolution of the scale factor in a flat FRW spacetime with a new generalized decay rule for the dynamic $\Lambda$-term under modified theories of gravity. It analyses certain cosmological parameters and examines their…

General Physics · Physics 2021-08-02 Anirudh Pradhan , De Avik , Tee How Loo , D. C. Maurya

In a four dimensional manifold formalism we study the evolutionary behavior as well as the ultimate fate of the universe, in the course of which the contribution of dark energy in these phases are investigated. At one stage we get a…

General Relativity and Quantum Cosmology · Physics 2018-11-13 Koijam Manihar Singh , Gauranga C. Samanta

We study the late time evolution of flat and negatively curved Friedmann-Robertson-Walker (FRW) models with a perfect fluid matter source and a scalar field arising in the conformal frame of $f(R)$ theories nonminimally coupled to matter.…

General Relativity and Quantum Cosmology · Physics 2010-04-14 Roberto Giambo' , John Miritzis

We explore the dynamics of FLRW cosmologies which consist of dark matter, radiation and dark energy with a quadratic equation of state. Standard cosmological singularities arise due to energy conditions which are violated by dark energy,…

General Relativity and Quantum Cosmology · Physics 2023-05-19 Molly Burkmar , Marco Bruni

R\'enyi Holographic Dark Energy (RHDE) Models has been studied in different dimensions considering a flat FRW metric, subsequently exploring the nature of evolution of different cosmological parameters. It is seen that the number of…

General Relativity and Quantum Cosmology · Physics 2022-02-22 A. Saha , A. Chanda , S. Dey , B. C. Paul , S. Ghose

We characterize a class of simple FRW models filled by both dark energy and dark matter in notion of a single potential function of the scale factor $a(t)$; $t$ is the cosmological time. It is representing potential of fictitious particle -…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marek Szydlowski , Aleksandra Kurek

Keeping in mind the current picture of an accelerating and flat Universe, some specific dynamical models of the cosmological term $\Lambda$ have been selected for investigating the nature of dark energy. Connecting the free parameters of…

Astrophysics · Physics 2008-11-26 Saibal Ray , Utpal Mukhopadhyay , Xin-He Meng

The presented paper is a comprehensive analysis of two dark energy (DE) cosmological models wherein exact solutions of the Einstein field equations (EFEs) are obtained in a model-independent way (or by cosmological parametrization). A…

General Physics · Physics 2022-07-20 S. K. J. Pacif

Specific dark energy models with a linear inhomogeneous time-dependent equation of state, within the framework of 4d Friedman-Robertson-Walker (FRW) cosmology, are investigated. It is demonstrated that such 4d inhomogeneous fluid models may…

General Relativity and Quantum Cosmology · Physics 2014-01-28 I. Brevik , A. V. Timoshkin , Ye. Rabochaya , S. Zerbini
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