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Related papers: Anisotropic Stars: Exact Solutions and Stability

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We investigate stable central structures in multiply-connected, anti de Sitter spacetimes with spherical, planar and hyperbolic geometries. We obtain an exact solution for the pressure in terms of the radius when the density is constant. We…

General Relativity and Quantum Cosmology · Physics 2009-10-31 W. L. Smith , R. B. Mann

The dissociation and ionization of hydrogen, during the formation of giant planets via core accretion, reduces the effective adiabatic index $\gamma$ of the gas and could trigger dynamical instability. We generalize the analysis of…

Earth and Planetary Astrophysics · Physics 2021-09-22 Suman Kumar Kundu , Eric R. Coughlin , Andrew N. Youdin , Philip J. Armitage

It is well known that a spherically symmetric constant density static star, modeled as a perfect fluid, possesses a bound on its mass m by its radial size R given by 2m/R \le 8/9 and that this bound continues to hold when the energy density…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Jemal Guven , Niall O' Murchadha

Two distinct non-singular interior models that describe anisotropic spherical configurations are presented in this work. We develop the Einstein field equations and the associated mass function in accordance with a static spherical…

General Relativity and Quantum Cosmology · Physics 2025-10-10 M. Sharif , Tayyab Naseer , Hira Shadab

We have provided here a new class of interior solutions for anisotropic stars admitting conformal motion in higher dimensional noncommutative spacetime. The Einstein fields equations are solved by choosing a particular density distribution…

General Relativity and Quantum Cosmology · Physics 2015-05-15 Piyali Bhar , Farook Rahaman , Saibal Ray , Vikram Chatterjee

In this work, an exact solution of Einstein's field equations in isotropic coordinates for anisotropic matter distribution is obtained by considering a particular metric choice of metric potential $g_{rr}$. To check the feasibility of the…

General Relativity and Quantum Cosmology · Physics 2022-06-29 B. S. Ratanpal , Bhavesh Suthar

This work is based on stability analysis of spherically symmetric collapsing star surrounding in locally anisotropic environment in $f(R,T)$ gravity, where $R$ is Ricci scalar and $T$ corresponds to the trace of energy momentum tensor.…

General Physics · Physics 2014-11-26 Ifra Noureen , M. Zubair

This manuscript examines viability and stability of anisotropic compact objects in the framework of $f(Q,L_m)$ gravity ($Q$ is the non-metricity and $L_m$ is the matter Lagrangian). We assume a particular functional form of this theory to…

General Relativity and Quantum Cosmology · Physics 2026-05-05 M. Sharif , M. Zeeshan Gul , Adeeba Arooj

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

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 investigate the properties of anisotropic white dwarf stars within the rainbow gravity adopting for matter content the Chandrasekhar model based on an ideal Fermi gas at zero temperature. We study in detail the effects of the anisotropic…

General Relativity and Quantum Cosmology · Physics 2024-11-20 Takol Tangphati , Grigoris Panotopoulos , Ayan Banerjee , Anirudh Pradhan

The equations describing the adiabatic, small radial oscillations of general relativistic stars are generalized to include the effects of a cosmological constant. The generalized eigenvalue equation for the normal modes is used to study the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 C. G. Boehmer , T. Harko

We present a spherically symmetric solution of the general relativistic field equations in isotropic coordinates for anisotropic neutral fluid, compatible with a super dense star modeling by considering a specific choice of anisotropy…

General Relativity and Quantum Cosmology · Physics 2014-10-23 Neeraj Pant , Narendra Pradhan , Manuel Malaver

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

The effects of the cosmological constant on the static equilibrium configurations and stability against small radial perturbations of relativistic polytropic spheres are investigated. This study numerically solves the hydrostatic…

General Relativity and Quantum Cosmology · Physics 2020-04-15 José D. V. Arbañil , Pedro H. R. S. Moraes

This paper analyzes the anisotropic stellar evolution governed by a polytropic equation of state in the framework of $f(R,T,Q)$ gravity, where $Q=R_{ab}T^{ab}$. We construct the field equations, hydrostatic equilibrium equation and trace…

General Relativity and Quantum Cosmology · Physics 2019-02-19 M. Sharif , Arfa Waseem

In this work, we have investigated anisotropic neutron stars in the framework of Rastall-Rainbow gravity. All our calculations were computed using the IU-FSU realistic equation of state (EoS), in which was considered two cases: standard…

High Energy Astrophysical Phenomena · Physics 2019-11-11 Clésio E. Mota , Luis C. N. Santos , Franciele M. da Silva , Cesar V. Flores , Tiago J. N. da Silva , Débora P. Menezes

Stationary stellar systems with radially elongated orbits are subject to radial orbit instability -- an important phenomenon that structures galaxies. Antonov (1973) presented a formal proof of the instability for spherical systems in the…

Astrophysics of Galaxies · Physics 2017-07-26 E. V. Polyachenko , I. G. Shukhman

We study the stability of three analytical solutions of the Einstein's field equations for spheres of fluid. These solutions are suitable to describe compact objects including white dwarfs, neutron stars and supermassive stars and they have…

General Relativity and Quantum Cosmology · Physics 2017-05-04 Ch. C. Moustakidis

A new class of solutions describing the composition of compact stars has been proposed, assuming that the fluid distribution inside the star is anisotropic. This is achieved by assuming the appropriate metric potential and then solving…

General Physics · Physics 2020-03-11 D. M. Pandya , B. Thakore , R. Goti , J. P. Rank , S. Shah