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In this paper, we develop a new class of models for a compact star with anisotropic stresses inside the matter distribution. By assuming a linear equation of state for the anisotropic matter composition of the star we solve the Einstein…

General Relativity and Quantum Cosmology · Physics 2021-11-16 Shyam Das , Saibal Ray , Maxim Khlopov , K. K. Nandi , Bikram Keshari Parida

In this work we obtain an analytic and well behaved solution to Einstein's field equations describing anisotropic matter distribution. It's achieved in the embedding class one spacetime framework using Karmarkar's condition. We ansatz the…

General Relativity and Quantum Cosmology · Physics 2018-10-29 Francisco Tello-Ortiz

In this present work, we have obtained a singularity-free spherically symmetric stellar model with anisotropic pressure in the background of Einstein's general theory of relativity. The Einstein's field equations have been solved by…

General Relativity and Quantum Cosmology · Physics 2021-06-23 Piyali Bhar , Pramit Rej , P. Mafa Takisa , M. Zubair

The aim of the research is to look into a new solution for isotropic compact stars in the context of the $f(R,\,T)$ theory of gravity. We used the Buchdahl [H.A. Buchdahl, Phys. Rev. {\bf 116} (1959) 1027] metric potentials as input to deal…

General Relativity and Quantum Cosmology · Physics 2024-03-21 Piyali Bhar , Pramit Rej

In this paper, we shall consider spherically symmetric spacetime solutions describing the interior of stellar compact objects, in the context of higher-order curvature theory of the f(R) type. We shall derive the non--vacuum field equations…

General Relativity and Quantum Cosmology · Physics 2021-06-28 G. G. L. Nashed , S. D. Odintsov , V. K. Oikonomou

We examine homogeneous but anisotropic cosmologies in scalar-tensor gravity theories, including Brans-Dicke gravity. We present a method for deriving solutions for any isotropic perfect fluid with a barotropic equation of state…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Jose P. Mimoso , David Wands

We study a gravitating spherically symmetric nonrelativistic configuration consisting of a spinor fluid whose effective equation of state is derived from a consideration of a limiting system supported by a massive nonlinear spinor field.…

General Relativity and Quantum Cosmology · Physics 2021-06-17 Vladimir Dzhunushaliev , Vladimir Folomeev

We extract new classes of anisotropic solutions in the framework of mimetic gravity, by applying the Tolman-Finch-Skea metric and a specific anisotropy not directly depending on it, and by matching smoothly the interior anisotropic solution…

General Relativity and Quantum Cosmology · Physics 2023-04-19 G. G. L. Nashed , Emmanuel N. Saridakis

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 model anisotropic neutron stars using three distinct prescriptions for pressure anisotropy, the Horvat, Bowers-Liang, and Covariant models, and three equations of state with different particle compositions, each described by a piecewise…

General Relativity and Quantum Cosmology · Physics 2025-12-24 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo , J. F. Rodriguez

In this paper we are concerned with the effects of anisotropic pressure on the boundary conditions of anisotropic Lane-Emden equation and homology theorem. Some new exact solutions of this equation are derived. Then some of the theorems…

General Relativity and Quantum Cosmology · Physics 2015-07-10 F. Shojai , M. R. Fazel , A. Estepanian , M. Kohandel

By a choice of new variables the pressure isotropy condition for spherically symmetric static perfect fluid spacetimes can be made a quadratic algebraic equation in one of the two functions appearing in it. Using the other variable as a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gyula Fodor

It is shown that an effective anisotropic spherically symmetric fluid model with heat flow can absorb the addition to a perfect fluid of pressure anisotropy, heat flow, bulk and shear viscosity, electric field and null fluid.

General Relativity and Quantum Cosmology · Physics 2009-12-15 B. V. Ivanov

This paper constructs three different anisotropic extensions of the existing isotropic solution to the modified field equations through the gravitational decoupling in $f(\mathbb{R},\mathbb{T})$ theory. For this, we take a static sphere…

General Relativity and Quantum Cosmology · Physics 2024-08-02 Tayyab Naseer , M. Sharif

We study the main astrophysical properties of differentially rotating neutron stars described as stationary and axisymmetric configurations of a moderately stiff $\Gamma=2$ polytropic fluid. The high level of accuracy and of stability of…

High Energy Astrophysical Phenomena · Physics 2017-03-08 Dorota Gondek-Rosinska , Izabela Kowalska , Loic Villain , Marcus Ansorg , Marcin Kucaba

I report on recent work concerning the existence and stability of self-gravitating spheres with anisotropic pressure. After presenting new exact solutions, Chandrasekhar's variational formalism for radial perturbations is generalized to…

Astrophysics · Physics 2009-11-10 Krsna Dev , Marcelo Gleiser

Much of the published work regarding the Isotropic Singularity is performed under the assumption that the matter source for the cosmological model is a barotropic perfect fluid, or even a perfect fluid with a $\gamma$-law equation of state.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Geoffery Ericksson , Susan M. Scott

One of the most common assumptions has been made that the pressure inside the star is isotropic in nature. However, the pressure is locally anisotropic in nature which is a more realistic case. In this study, we investigate certain…

General Relativity and Quantum Cosmology · Physics 2022-11-18 H. C. Das

In this work, we provide a novel exact solution to the Einstein-Maxwell field equations in isotropic coordinates for charged anisotropic matter distribution, achieved by considering one of the metric potentials as well as a particular form…

General Relativity and Quantum Cosmology · Physics 2025-08-25 B S Ratanpal , Bhavesh Suthar

In this study, we demonstrate a new anisotropic solution to the Einstein field equations in Finch-Skea spacetime. The physical features of stellar configuration are studied in previous investigations. We create a model that meets all…

General Relativity and Quantum Cosmology · Physics 2023-06-28 Ankita Jangid , B. S. Ratanpal , K Venkataratnam Kamma