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Related papers: Dynamical instability and the expansion-free condi…

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We study the dynamical instability of anisotropic collapsing cylinder with the expansion-free condition, which generates vacuum cavity within fluid distribution. The perturbation scheme is applied to distinguish Newtonian, post-Newtonian…

General Relativity and Quantum Cosmology · Physics 2015-06-16 M. Sharif , M. Azam

This paper investigates instability ranges of a cylindrically symmetric collapsing stellar object in Brans-Dicke theory of gravity. For this purpose, we use perturbation approach in the modified field equations as well as dynamical…

General Relativity and Quantum Cosmology · Physics 2016-07-20 M. Sharif , Rubab Manzoor

We study the spherically symmetric collapsing star in terms of dynamical instability. We take the framework of extended teleparallel gravity with non-diagonal tetrad, power-law form of model presenting torsion and matter distribution as…

General Relativity and Quantum Cosmology · Physics 2016-03-16 Abdul Jawad , Shamaila Rani

The objective of this paper is to discuss the dynamical instability in the context of Newtonian and post Newtonian regimes. For this purpose, we consider non-viscous heat conducting charged isotropic fluid as a collapsing matter with…

General Relativity and Quantum Cosmology · Physics 2015-06-04 M. Sharif , M. Azam

The problem of the dynamical stability of anistropic systems is studied, by proposing a criterion in terms of the adiabatic local index $\gamma$. The result has general validity and can be applied to several physical situations.…

General Relativity and Quantum Cosmology · Physics 2019-02-14 Giuseppe Alberti , Marco Merafina

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

In this paper, we analyze stability regions of a non-static restricted class of axially symmetric spacetime with anisotropic matter distribution. We consider $f(R)=R+{\epsilon}R^2$ model and assume hydrostatic equilibrium of the axial…

General Relativity and Quantum Cosmology · Physics 2014-11-19 M. Sharif , Z. Yousaf

In this paper, we have analyzed the stability of cylindrically symmetric collapsing object filled with locally anisotropic fluid in $f(R,T)$ theory, where $R$ is the scalar curvature and $T$ is the trace of stress-energy tensor of matter.…

General Physics · Physics 2018-11-15 M. Zubair , Hina Azmat , Ifra Noureen

We investigate the conditions for the (in)stability of the isotropic pressure condition in collapsing spherically symmetric, dissipative fluid distributions. It is found that dissipative fluxes, and/or energy density inhomogeneities and/or…

General Relativity and Quantum Cosmology · Physics 2020-05-27 L. Herrera

The implications of shearfree condition on instability range of anisotropic fluid in $f(R,T)$ are studied in this manuscript. A viable $f(R, T)$ model is chosen to arrive at stability criterion, where $R$ is Ricci scalar and $T$ is the…

General Relativity and Quantum Cosmology · Physics 2015-07-29 Ifra Noureen , M. Zubair , A. A. Bhatti , G. Abbas

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

We consider spherically symmetric spacetimes sourced by a fluid with pressure anisotropy in the radial direction. We use gauge-invariant perturbation theory to study the stability of this class of spacetimes under axial perturbations. We…

General Relativity and Quantum Cosmology · Physics 2014-07-23 Bhavesh Khamesra , V Suneeta

We study the dynamical stability of self-gravitating systems in presence of anisotropy. In particular, we introduce a stability criterion, in terms of the adiabatic local index, that generalizes the stability condition $<\gamma> \geq 4/3$…

General Relativity and Quantum Cosmology · Physics 2022-06-29 Giuseppe Alberti

In this paper, we explore instability regions of non-static axial reflection symmetric spacetime with anisotropic source in the interior. We impose linear perturbation on the Einstein field equations and dynamical equations to establish the…

General Physics · Physics 2015-12-16 M. Sharif , M. Zaeem Ul Haq Bhatti

In this paper, we have continued the work of Herrera \emph{et al.} \cite{herrera2012dynamical} in $f(G)$ gravitational theory. For this purpose, a spherically symmetric fluid exhibiting locally anisotropic pressure along with the energy…

General Relativity and Quantum Cosmology · Physics 2020-05-19 M. Z. Bhatti , Z. Yousaf , A. Khadim

Dynamical analysis of spherically symmetric collapsing star surrounding in locally anisotropic environment with expansion-free condition is presented in $f(R,T)$ gravity, where $R$ corresponds to Ricci scalar and $T$ stands for the trace of…

General Relativity and Quantum Cosmology · Physics 2015-04-21 Ifra Noureen , M. Zubair

This paper is devoted to analyze the dynamical instability of a self-gravitating object undergoes to collapse process. We take the framework of generalized teleparallel gravity with cylindrically symmetric gravitating object. The matter…

General Relativity and Quantum Cosmology · Physics 2016-10-31 Abdul Jawad , Davood Momeni , Shamaila Rani , Ratbay Myrzakulov

In this paper, we discuss the effects of electromagnetic field on the dynamical instability of a spherically symmetric expansionfree gravitational collapse. Darmois junction conditions are formulated by matching interior spherically…

General Relativity and Quantum Cosmology · Physics 2015-06-16 M. Sharif , M. Azam

In this paper, we study the effects of modification of gravity on the problem of dynamical instability of the spherical relativistic anisotropic interiors. We have considered non-zero influence of expansion scalar throughout during the…

General Relativity and Quantum Cosmology · Physics 2018-07-17 Z. Yousaf , Kazuharu Bamba , M. Z. Bhatti , U. Farwa

This paper investigates dynamics of axial reflection symmetric model in self-interacting Brans-Dicke gravity for anisotropic fluid. We formulate hydrodynamical equations and discuss oscillations using time-dependent perturbation for both…

General Relativity and Quantum Cosmology · Physics 2016-07-22 M. Sharif , Rubab Manzoor
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