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Related papers: Anisotropic Quintessence stars

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We have constructed star models consisting of four parts: (i) a homogeneous inner core with anisotropic pressure (ii) an infinitesimal thin shell separating the core and the envelope; (iii) an envelope of inhomogeneous density and isotropic…

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

A class of general relativistic solutions in isotropic spherical polar coordinates are discussed which describe compact stars in hydrostatic equilibrium. The stellar models obtained here are characterized by four parameters, namely,…

Solar and Stellar Astrophysics · Physics 2015-06-17 Rumi Deb , Bikash Chandra Paul , Ramesh Tikekar

A physically realistic stellar model with a simple expression for the energy density and conformally flat interior is found. The relations between the different physical conditions are used without graphic proofs. It may represnet a real…

General Relativity and Quantum Cosmology · Physics 2018-04-26 B. V. Ivanov

In this talk we present a model of the universe in which dark energy is modelled explicitely with both a dynamical quintessence field and a cosmological constant. Our results confirm the possibility of a collapsing universe (for a given…

Astrophysics · Physics 2007-05-23 Rolando Cardenas , Tame Gonzalez , Osmel Martin , Israel Quiros

In this work we provide a framework for modeling compact stars in which the interior matter distribution obeys a generalised Chaplygin equation of state. The interior geometry of the stellar object is described by a spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2016-05-05 Piyali Bhar , Megan Govender , Ranjan Sharma

The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original…

High Energy Astrophysical Phenomena · Physics 2017-06-30 José D. V. Arbañil , M. Malheiro

We present a comprehensive study of the observational constraints on spatially flat cosmological models containing a mixture of matter and quintessence --- a time varying, spatially inhomogeneous component of the energy density of the…

Astrophysics · Physics 2009-09-15 Limin Wang , R. R. Caldwell , J. P. Ostriker , Paul J. Steinhardt

In this paper, we study the impact of anisotropy on neutron stars with different equations of state, which have been modeled by a piecewise polytropic function with continuous sound speed. Anisotropic pressure in neutron stars is often…

High Energy Astrophysical Phenomena · Physics 2024-01-22 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo

In this paper, we consider the mimetic gravitational theory to derive a novel category of anisotropic star models. To end and to put the resulting differential equations into a closed system, the form of the metric potential $g_{rr}$ as…

General Relativity and Quantum Cosmology · Physics 2021-10-11 G. G. L. Nashed

We obtain a class of new anisotropic relativistic solution in Einstein Gauss-Bonnet (EGB) gravity with Finch-Skea metric in hydrostatic equilibrium. The relativistic solutions are employed to construct anisotropic stellar models for strange…

General Relativity and Quantum Cosmology · Physics 2022-01-26 Sagar Dey , Bikash Chandra Paul

In the present paper, we treat the problem of the existence of quark stars (QSs) for selected homogeneous and unpaired charge-neutral $3$-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections equations of state (EoS). Using…

General Relativity and Quantum Cosmology · Physics 2021-06-02 Grigoris Panotopoulos , Takol Tangphati , Ayan Banerjee , M. K. Jasim

In this paper, we have studied the stability of the cosmological models with dark energy and combination of matter fields and dark energy in an anisotropic space time. The pressure anisotropy along the spatial directions are derived and its…

General Relativity and Quantum Cosmology · Physics 2021-03-02 B. Mishra , Fakhereh Md. Esmaeili , Pratik P. Ray , S. K. Tripathy

In this paper, we study the physical characteristics of anisotropic spherically symmetric quark star candidates for $R+2\sigma T$ gravity model, where $R$, $\sigma$ and $T$ depict scalar curvature, coupling parameter, and the trace of the…

General Relativity and Quantum Cosmology · Physics 2020-01-08 M. Sharif , Arfa Waseem

Present paper deals with the composition and modelling of compact dense astrophysical bodies under the framework of $f(R)$ gravity. The model is employed on various observed strange stars viz., SMC X-1, SAX J1808.4-3658, Swift J1818.0-1607,…

General Relativity and Quantum Cosmology · Physics 2020-08-12 B. Thakore , R. Goti , S. Shah , H. Pandya , D. M. Pandya

In this paper, we study the viability and stability of anisotropic compact stars in the context of $f(\mathcal{Q})$ theory, where $\mathcal{Q}$ is non-metricity scalar. We use Finch-Skea solutions to investigate the physical properties of…

General Relativity and Quantum Cosmology · Physics 2024-01-18 Muhammad Zeeshan Gul , Shamaila Rani , Muhammad Adeel , Abdul Jawad

In present paper a spherically symmetric stellar configuration has been analyzed by assuming the matter distribution of the stellar configuration is anisotropic in nature and compared with the realistic objects, namely, the low mass X-ray…

General Relativity and Quantum Cosmology · Physics 2021-08-26 Piyali Bhar , Tuhina Manna , Farook Rahaman , Ayan Banerjee

In this study we explore the astrophysical implications of pressure anisotropy on the physical characteristics of millisecond pulsars within the framework of $f(Q)$ gravity, {in particular $f(Q)=-\alpha\, Q - \beta$, where $\alpha$ and…

General Relativity and Quantum Cosmology · Physics 2024-10-08 S. K. Maurya , Ksh. Newton Singh , G. Mustafa , M. Govender , Abdelghani Errehymy , Abdul Aziz

We develop the formalism for determining the quasinormal modes of general relativistic multi-fluid compact stars in such a way that the impact of superfluid gap data can be assessed. Our results represent the first attempt to study true…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Lap-Ming Lin , N. Andersson , G. L. Comer

We constrain cosmological parameters in flat cosmologies with tracking dark energy (or Quintessence) using the existing data on Cosmic Microwave Background (CMB) anisotropies. We perform a maximum likelihood analysis using combined data…

We study a dark energy model with non-zero anisotropic stress, either linked to the dark energy density or to the dark matter density. We compute approximate solutions that allow to characterise the behaviour of the dark energy model and to…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Wilmar Cardona , Lukas Hollenstein , Martin Kunz
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