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Related papers: Expansionfree Fluid Evolution and Skripkin Model i…

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We consider a collapsing sphere and discuss its evolution under the vanishing expansion scalar in the framework of $f(R)$ gravity. The fluid is assumed to be locally anisotropic which evolves adiabatically. To study the dynamics of the…

General Physics · Physics 2015-06-03 M. Sharif , H. Rizwana Kausar

We study the equations for the evolution of cosmological perturbations in $f\left(\mathcal{R}\right)$ and conclude that this modified gravity model can be expressed as a dark energy fluid at background and linearised perturbation order. By…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 R. A. Battye , B. Bolliet , J. A. Pearson

Spherically symmetric expansionfree distributions are systematically studied. The whole set of field equations and junction conditions are presented for a general distribution of dissipative anisotropic fluid (principal stresses unequal),…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Herrera , N. O. Santos , A. Wang

Dark energy models based on f(R) theory have been extensively studied in literature to realize the late time acceleration. In this paper, we have chosen a viable f(R) model and discussed its effects on the dynamical instability of…

General Relativity and Quantum Cosmology · Physics 2015-05-30 M. Sharif , H. Rizwana Kausar

This paper is devoted to investigate the cylindrical collapse of an anisotropic fluid in $f(R)$ gravity. For this purpose, the viscous charged anisotropic fluid dissipating energy with heat flow and shear is assumed. We use the perturbation…

General Relativity and Quantum Cosmology · Physics 2017-12-07 M. Farasat Shamir , M. Atif Fayyaz

In this paper, we investigate spherically symmetric perfect fluid gravitational collapse in metric $f(R)$ gravity. We take non-static spherically symmetric metric in the interior region and static spherically symmetric metric in the…

General Relativity and Quantum Cosmology · Physics 2011-01-17 M. Sharif , H. Rizwana Kausar

The starting point in this note is $f(R)$ modified gravity in a cosmological setting. We assume a spatially flat Universe to describe late-time cosmology and the perfect-fluid equation of state $p=\omega\rho$ to model the hypothesized dark…

General Relativity and Quantum Cosmology · Physics 2017-06-13 Peter K. F. Kuhfittig

In a recent paper a systematic study on shearing expansion-free spherically symmetric distributions was presented. As a particular case of such systems, the Skripkin model was mentioned, which corresponds to a nondissipative perfect fluid…

General Relativity and Quantum Cosmology · Physics 2015-05-13 L. Herrera , G. Le Denmat , N. O. Santos

This paper is about the $n+2$-dimensional gravitational contraction of inhomogeneous fluid without heat flux in the framework of $f(R)$ metric theory of gravity. Matching conditions for two regions of a star has been derived by using the…

General Relativity and Quantum Cosmology · Physics 2017-08-02 G. Abbas , M. S. Khan , Zahid Ahmad , M. Zubair

We consider static spherically symmetric self-gravitating configurations of the perfect fluid within the framework of the torsion-based extended theory of gravity. In particular, we use the covariant formulation of $f(T)$ gravity with $f(T)…

General Relativity and Quantum Cosmology · Physics 2018-10-03 Sasa Ilijic , Marko Sossich

We study the implications of $R^n$ extension of Starobinsky model on dynamical instability of Vorticity-free axially symmetric gravitating body. The matter distribution is considered to be anisotropic for which modified field equations are…

General Relativity and Quantum Cosmology · Physics 2015-04-13 Ifra Noureen , Abdul Aziz Bhatti , M. Zubair

Within the limits of the present cosmological observations in f(R,T) gravity theory, we have analyzed a spherically symmetric space-time in 5D setting. The field equations have been carefully studied considering reasonable cosmological…

General Relativity and Quantum Cosmology · Physics 2020-10-28 Pheiroijam Suranjoy Singh , Kangujam Priyokumar Singh

This work is aimed to explore the dark dynamical effects of $f(R,T)$ modified gravity theory on the dynamics of compact celestial star. We have taken the interior geometry as spherical star which is filled with imperfect fluid distribution.…

General Relativity and Quantum Cosmology · Physics 2017-11-09 M. Z. Bhatti , Z. Yousaf , M. Ilyas

We consider a modified gravity theory, $f(R)=R+\alpha R^n-\frac{\mu^4}{R^m}$, in the metric formulation and analyze the contribution of electromagnetic field on the range of dynamical instability of a star filled with anisotropic matter.…

General Physics · Physics 2015-10-22 H. Rizwana Kausar , Ifra Noureen , M. Umair Shahzad

The collapsing dynamics of relativistic fluid are explored in $f(R)$ gravity in a detailed systematic manner for the non-static spherically symmetric spacetime satisfying the equation of the conformal Killing vector. With quasi-homologous…

General Relativity and Quantum Cosmology · Physics 2024-10-03 Kazuharu Bamba , Z. Yousaf , M. Z. Bhatti , R. Nazer , Yuki Hashimoto

In this article, we considered the bulk viscous fluid in the formalism of modified gravity in which the general form of a gravitational action is $f(R, T)$ function, where $R$ is the curvature scalar and $T$ is the trace of the energy…

General Relativity and Quantum Cosmology · Physics 2017-08-02 G. C. Samanta , R. Myrzakulov

This study examines the dynamical evolution of self-gravitating systems in the presence of exotic matter within the framework of $f(R)$ gravity. Specifically, we have adopted the Starobinsky model $f(R) = R + \alpha R^2$, which incorporates…

General Relativity and Quantum Cosmology · Physics 2025-11-18 A. Zahra , S. A. Mardan , Muhammad Bilal Riaz , Javlon Rayimbaev , Inomjon Ibragimov , Munisbek Akhmedov , Erkaboy Davletov

Here we study the essence of $f(R,T)$ gravitation theory in five dimensional Universe and see the role of dark energy in the form of wet dark fluid in such a Universe. It is found that the dark energy is not exaggerated in contributing to…

General Physics · Physics 2019-07-09 Koijam Manihar Singh , S. Surendra Singh , Leishingam Kumrah

In the present work, gravitational collapse of an inhomogeneous spherical star model, consisting of inhomogeneous dust fluid (dark matter) in the background of dark energy is considered. The collapsing process is examined first separately…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Tanwi Bandyopadhyay , Subenoy Chakraborty

This paper explores the dynamics of evolving cluster of stars in the presences of exotic matter. The $f(R)$ theory is used to presume exotic terms for evolution scenario. We use structure scalars as evolution parameters to explore dynamics…

General Relativity and Quantum Cosmology · Physics 2021-12-23 Rubab Manzoor , Wasee Shahid
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