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Related papers: Comment to ''On Anisotropic Dark Energy Stars''

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Since the discovery of the accelerated expansion of the universe, it was necessary to introduce a new component of matter distribution called dark energy. The standard cosmological model considers isotropy of the pressure and assumes an…

General Relativity and Quantum Cosmology · Physics 2012-10-25 R. Chan , M. F. A. da Silva , J. F. Villas da Rocha

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

A variety of observational tests seem to suggest that the universe is anisotropic. This is incompatible with the standard dogma based on adiabatic, rotationally invariant perturbations. We point out that this is a consequence of the…

Astrophysics · Physics 2009-11-11 Richard A. Battye , Adam Moss

Spherically symmetric relativistic stars with the polytropic equation of state (EoS), which possess the local pressure anisotropy, are considered within the framework of general relativity. The generalized Lane-Emden equations are derived…

General Relativity and Quantum Cosmology · Physics 2018-01-12 A. A. Isayev

Spherically symmetric relativistic stars with the polytropic equation of state, which possess the local pressure anisotropy, are considered in the context of general relativity. The modified Lane-Emden equations are derived for the special…

General Relativity and Quantum Cosmology · Physics 2018-01-25 A. A. Isayev

In this paper, we constrain dark energy models using a compendium of observations at low redshifts. We consider the dark energy as a barotropic fluid, with the equation of state a constant as well the case where dark energy equation of…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Ashutosh Tripathi , Archana Sangwan , H. K. Jassal

We propose a model for an anisotropic dark energy star where we assume that the radial pressure exerted on the system due to the presence of dark energy is proportional to the isotropic perfect fluid matter density. We discuss various…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Farook Rahaman , Anil Kumar Yadav , Saibal Ray , Raju Maulick , Ranjan Sharma

By employing modified Chaplygin fluid prescription for the dark energy, we construct slowly rotating isotropic and anisotropic dark energy stars. The slow rotation is incorporated via general relativistic Hartle-Thorne formalism; whereas…

General Relativity and Quantum Cosmology · Physics 2024-07-26 O. P. Jyothilakshmi , Lakshmi J. Naik , V. Sreekanth

We investigate the anisotropic parameterization of the dark energy equation of state within the framework of an axisymmetric (planar) Bianchi-I universe. Using the latest Pantheon+ Type Ia Supernova dataset, augmented by SH0ES Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Anshul Verma , Pavan K. Aluri , David F. Mota

A model of compact object coupled to inhomogeneous anisotropic dark energy is studied. It is assumed a variable dark energy that suffers a phase transition at a critical density. The anisotropic Lambda-Tolman-Oppenheimer-Volkoff equations…

General Relativity and Quantum Cosmology · Physics 2011-05-12 Cristian R. Ghezzi

We investigate the spacetime of anisotropic stars admitting conformal motion. The Einstein field equations are solved using different ansatz of the surface tension. In this investigation, we study two cases in details with the anisotropy…

Astrophysics · Physics 2009-12-15 Farook Rahaman , Mubasher Jamil , Mehedi Kalam , Kaushik Chakraborty , Ashis Ghosh

We investigate the possibility of using cosmological observations to probe and constrain an imperfect dark energy fluid. We consider a general parameterization of the dark energy component accounting for an equation of state, speed of sound…

Astrophysics · Physics 2008-12-18 D. F. Mota , J. R. Kristiansen , T. Koivisto , N. E. Groeneboom

We propose a relativistic model for quintessence stars with the combination of an anisotropic pressure corresponding to normal matter and a quintessence dark energy having a characteristic parameter {\omega}q such that -1 <{\omega}q < -…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Mehedi Kalam , Farook Rahaman , Sajahan Molla , Sk. Monowar Hossein

Dark energy stars research is an issue of great interest since recent astronomical observations with respect to measurements in distant supernovas, cosmic microwave background and weak gravitational lensing confirm that the universe is…

General Relativity and Quantum Cosmology · Physics 2021-06-18 M. Malaver , H. D. Kasmaei , R. Iyer , S. Sadhukhan , A. Kar

New exact solutions of Einstein's field equations (EFEs) by assuming linear equation of state, $ p_r = \alpha (\rho - \rho_R) $ where $ p_r $ is the radial pressure and $ \rho_R $ is the surface density, are obtained on the background of a…

General Physics · Physics 2017-06-28 V. O. Thomas , D. M. Pandya

The possibility of strange stars mixed with dark energy to be one of the candidates for dark energy stars is the main issue of the present study. Our investigation shows that quark matter acts as dark energy after a certain yet unknown…

General Relativity and Quantum Cosmology · Physics 2021-11-15 Theophanes Grammenos , Farook Rahamn , Saibal Ray , Debabrata Deb , Sourav Roy Chowdhury

As the stars carry electrical charges, we present in this paper a model for charged dark energy star which is singularity free. We take Krori-Barua space time. We assume that the radial pressure exerted on the system due to the presence of…

General Physics · Physics 2015-06-19 Kanika Das , Nawsad Ali

We investigate the consequences of an imperfect dark energy component on the large scale structure. A phenomenological three parameter fluid description is used to study the effect of dark energy on the cosmic microwave background radiation…

Astrophysics · Physics 2009-11-13 Tomi Koivisto , David F. Mota

We study the non-radial $f$-mode oscillations of both isotropic and anisotropic dark energy stars by using the modified Chaplygin prescription of dark energy to model the stellar matter. The anisotropic pressure in the system is modeled…

General Relativity and Quantum Cosmology · Physics 2024-07-23 O. P. Jyothilakshmi , Lakshmi J. Naik , V. Sreekanth

We examine the class of barotropic fluid models of dark energy, in which the pressure is an explicit function of the density, p = f(\rho). Through general physical considerations we constrain the asymptotic past and future behaviors and…

Astrophysics · Physics 2010-04-21 Eric V. Linder , Robert J. Scherrer
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