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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

An infinite class of exact static anisotropic spheres is developed. All members of the class satisfy (i) regularity (meaning no singularities), and in particular at the origin, (ii) positive but monotone decreasing energy density…

General Relativity and Quantum Cosmology · Physics 2016-06-13 Kayll Lake

The semiclassical approximation takes into account the gravitational contribution of zero-point energies. We model this contribution via the renormalized stress-energy tensor (RSET) of a massless scalar field, which we compute in a…

General Relativity and Quantum Cosmology · Physics 2021-11-01 Julio Arrechea , Carlos Barceló , Raúl Carballo-Rubio , Luis J. Garay

The main aim of this study is to examine the behaviour of physical parameters of an anisotropic compact star model demonstrating spherical symmetry in F(Q) modified gravity. To evaluate the behaviour and the stability of an anisotropic…

General Relativity and Quantum Cosmology · Physics 2025-05-26 Sat Paul , Jitendra Kumar , S. K. Maurya

We present a covariant and gauge-invariant formulation of the theory of radial adiabatic linear perturbations of self-gravitating, non-dissipative imperfect fluids within the theory of general relativity. By codifying the thermodynamical…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Paulo Luz , Sante Carloni

The general form of the anisotropy parameter of the expansion for Bianchi type-III metric is obtained in the presence of a single diagonal imperfect fluid with a dynamically anisotropic equation of state parameter and a dynamical energy…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Ozgur Akarsu , Can B. Kilinc

Using a general solution-generating technique for electrically charged relativistic stars with spherical symmetry, we derive a new bound on the mass-radius ratio. This compactness bound is based on the already established bounds for…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Cristian Stelea , Marina-Aura Dariescu , Ciprian Dariescu

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

We give the first general construction of solutions of the static spherically symmetric Einstein-Euler equations, the Tolman-Oppenheimer-Volkoff (TOV-)equation, with prescribed density functions allowed to be discontinuous and non-uniform;…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Moritz Reintjes , Ruochen Xia

Simple generic extensions of isotropic Durgapal--Fuloria stars to the anisotropic domain are presented. These anisotropic solutions are obtained by guided minimal deformations over a self gravitating isotropic system. When the isotropic and…

General Relativity and Quantum Cosmology · Physics 2018-07-04 Luciano Gabbanelli , Ángel Rincón , Carlos Rubio

In the present article authors investigate the anisotropic stellar solutions admitting Finch-Skea symmetry (viable and non-singular metric potentials) in the presence of some exotic matter fields, such as: Bose-Einstein Condensate (BEC)…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Oleksii Sokoliuk , Alexander Baransky , P. K. Sahoo

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

The main aim of this paper is to obtain a completely new relativistic non-singular model for static, spherically symmetric isotropic celestial compact stars in the $f(R, T)$ gravity scenario. In this regard, we have considered the isotropic…

General Relativity and Quantum Cosmology · Physics 2024-01-17 Nayan Sarkar , Susmita Sarkar , Banashree Sen Moumita Sarkar , Farook Rahaman

If the augmented density of a spherical anisotropic system is assumed to be multiplicatively separable to functions of the potential and the radius, the radial function, which can be completely specified by the behavior of the anisotropy…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-21 J. An

We use gravitational wave (GW) and electromagnetic (EM) observations of GW170817 to constrain the extent of pressure anisotropy in it. While it is quite likely that the pressure inside a neutron star is mostly isotropic, certain physical…

General Relativity and Quantum Cosmology · Physics 2019-05-08 Bhaskar Biswas , Sukanta Bose

I deduce an exact and analytic Bianchi type I solution of Einsteins field equations, which generalizes the isotropic LambdaCDM universe model to a corresponding model with anisotropic expansion. The main point of the article is to present…

General Relativity and Quantum Cosmology · Physics 2024-06-17 Øyvind G. Grøn

The present work is devoted to the study of anisotropic compact matter distributions within the framework of 5-dimensional Einstein-Gauss-Bonnet gravity. To solve the field equations, we have considered that the inner geometry is described…

General Physics · Physics 2020-01-08 Piyali Bhar , Ksh. Newton Singh , Francisco Tello-Ortiz

The main focus of this paper is to discuss the solutions of Einstein-Maxwell's field equations for compact stars study. We have chosen the MIT bag model equation of state for the pressure-energy density relationship and conformal Killing…

General Relativity and Quantum Cosmology · Physics 2020-11-16 M. Farasat Shamir

We investigate the effects of multiple anisotropic light scattering by interstellar dust particles on photometric profiles of disk galaxy models computed using an iterative ray-tracing radiative transfer modeling code. It is shown that…

Astrophysics · Physics 2007-05-23 D. Semionov , V. Vansevicius

The equilibrium configurations of slowly rotating anisotropic self-gravitating fluids are computed using the extended Hartle structure equations, including anisotropic effects, derived in our previous paper. We focus on the so-called…

General Relativity and Quantum Cosmology · Physics 2025-10-20 Philip Beltracchi , Camilo Posada