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This paper aims to examine the composition of various spherically symmetric star models which are coupled with anisotropic configuration in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ gravity, where…

General Relativity and Quantum Cosmology · Physics 2024-07-03 M. Sharif , T. Naseer

We investigate the physical and observational features of static, spherically symmetric black hole spacetimes surrounded by anisotropic fluid and embedded in a plasma environment. Motivated by recent advances in black hole imaging and…

General Relativity and Quantum Cosmology · Physics 2025-12-15 Jonibek Khasanov , Mirzabek Alloqulov , Pankaj Sheoran , Sanjar Shaymatov , Hemwati Nandan

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 the present paper we develop an algorithm for all spherically symmetric anisotropic charged fluid distribution. Considering a new source function $\nu(r)$ we find out a set of solutions which is physically well behaved and represent…

General Relativity and Quantum Cosmology · Physics 2017-06-12 S. K. Maurya , Y. K. Gupta , Saibal Ray

This paper is devoted to study the analytic models of anisotropic compact stars in $f(T)$ gravity (where $T$ is torsion scalar), with non-diagonal tetrad. By taking the anisotropic source inside the spherically symmetric star, the equations…

General Physics · Physics 2016-01-20 M. Zubair , G. Abbas

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

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 consider the general situation of a compact relativistic body with anisotropic pressures in the presence of the electromagnetic field. The equation of state for the matter distribution is linear and may be applied to strange stars with…

General Relativity and Quantum Cosmology · Physics 2009-01-16 S. Thirukkanesh , S. D. Maharaj

Interior structures of stellar objects might have small pressure anisotropy due to several reasons, including rotation and the presence of magnetic fields. Here, retaining the approximation of spherical symmetry, we study the possible role…

Solar and Stellar Astrophysics · Physics 2019-11-06 Shaswata Chowdhury , Tapobrata Sarkar

Model of gravitational collapse of anisotropic compact stars in a new theory of $ f(R) $ gravity has been developed. The author considers the modified gravity model of $ f(R) = \xi R^4 $ to investigate a physically acceptable model of…

General Relativity and Quantum Cosmology · Physics 2022-04-01 Jay Solanki

Some models (such as the Skyrme model, a low-energy effective field theory for QCD) suggest that the high-density matter prevailing in neutron star interiors may be significantly anisotropic. Anisotropy is known to affect the bulk…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Hector O. Silva , Caio F. B. Macedo , Emanuele Berti , Luís C. B. Crispino

We study Bianchi cosmologies in the ghost-free bigravity theory assuming both metrics to be homogeneous and anisotropic, of the Bianchi class A, which includes types I,II,VI$_0$,VII$_0$,VIII, and IX. We assume the universe to contain a…

High Energy Physics - Theory · Physics 2013-11-08 Kei-ichi Maeda , Mikhail S. Volkov

In this manuscript, we investigate the oscillatory behaviour of the anisotropy in the diagonal Bianchi-I spacetimes. Our starting point is a simplification of Einstein's equations using only observable or physical variables. As a…

General Relativity and Quantum Cosmology · Physics 2021-04-02 Leandro G Gomes , Bruno B. Bizarria , Gabriel A. de Souza Silva , William O. Clavijo

We consider a cosmological model in which the two major fluid components of the Universe, dark energy and dark matter, flow with distinct four-velocities. This cosmological configuration is equivalent to a single anisotropic fluid,…

General Relativity and Quantum Cosmology · Physics 2013-07-24 Tiberiu Harko , Francisco S. N. Lobo

We extend a known solution generating technique for isotropic fluids in order to construct more general models of anisotropic stars with poloidal magnetic fields. In particular, we discuss the magnetized versions of some well-known exact…

General Relativity and Quantum Cosmology · Physics 2018-06-06 Cristian Stelea , Marina-Aura Dariescu , Ciprian Dariescu

Einstein's theory of general relativity predicts that the only stationary configuration of an isolated black hole is the Kerr spacetime, which has a unique multipolar structure and a spherical shape when non-spinning. This is in striking…

General Relativity and Quantum Cosmology · Physics 2020-09-02 Guilherme Raposo , Paolo Pani

We present a model of compact astrophysical object under General Theory of Relativity using the anisotropic extension of Tolman IV solution. The anisotropy function, derived from the model, remains well behaved throughout the interior of…

General Relativity and Quantum Cosmology · Physics 2022-06-29 Shyam Das , Bikram Keshari Parida , Koushik Chakraborty , Saibal Ray

We study black holes with linear equation of state within the framework of asymptotically safe gravity. This study extends previous work on gravitational collapse in asymptotically safe gravity (that has been done for a dust fluid) by…

General Relativity and Quantum Cosmology · Physics 2026-02-17 Ramin Hassannejad , Fatimah Shojai , Kazuharu Bamba

We study gravitational collapse with anisotropic pressures, whose end stage can mimic space-times that are seeded by galactic dark matter. To this end, we identify a class of space-times (with conical defects) that can arise out of such a…

Astrophysics of Galaxies · Physics 2017-08-30 Uddipan Banik , Dipanjan Dey , Kaushik Bhattacharya , Tapobrata Sarkar

It has been known that a non-perfect fluid that accounts for dissipative viscous effects can evade a highly anisotropic chaotic mixmaster approach to a singularity. Viscosity is often simply parameterised in this context, so it remains…

General Relativity and Quantum Cosmology · Physics 2022-02-02 Chandrima Ganguly , Jerome Quintin