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We study spherically symmetric spacetimes for matter distributions with isotropic pressures. We generate new exact solutions to the Einstein field equations which also contains isotropic pressures. We develop an algorithm that produces a…

General Relativity and Quantum Cosmology · Physics 2014-12-23 S. Ngubelanga , S. D. Maharaj

This paper develops some new analytical solutions to the $f(\mathbb{R},\mathbb{T})$ field equations through extended gravitational decoupling. For this purpose, we take spherical anisotropic configuration as a seed source and extend it to…

General Relativity and Quantum Cosmology · Physics 2023-02-15 M. Sharif , Tayyab Naseer

This paper uses the definition of complexity for a static spherically symmetric spacetime and extends it to the case of charged distribution. We formulate the Einstein-Maxwell field equations corresponding to the anisotropic interior and…

General Relativity and Quantum Cosmology · Physics 2023-06-02 M. Sharif , Tayyab Naseer

We investigate the impact of an external pressure on the structure of self-gravitating polytropes for axially symmetric ellipsoids and rings. The confinement of the fluid by photons is accounted for through a boundary condition on the…

Solar and Stellar Astrophysics · Physics 2017-11-15 J. -M. Huré , F. Hersant , G. Nasello

It is shown how the well-known formula for the gravitational energy of self-gravitating regular polytropes of finite mass can be obtained in an elementary way by using Gauss's divergence theorem and the Chandrasekhar virial tensor, without…

Solar and Stellar Astrophysics · Physics 2025-10-15 Luca Ciotti

A new solution with constant torsion is derived using the field equations of f(T). Asymptotic forms of energy density, radial and transversal pressures are shown to meet the standard energy conditions, i.e., weak and null energy conditions…

General Physics · Physics 2016-10-24 Gamal G. L. Nashed

We establish an algorithm that produces a new solution to the Einstein field equations, with an anisotropic matter distribution, from a given seed isotropic solution. The new solution is expressed in terms of integrals of known functions,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. D. Maharaj , M. Chaisi

A family of spin-lattice models are derived as convergent finite dimensional approximations to the rest frame kinetic energy of a barotropic fluid coupled to a massive rotating sphere. In not fixing the angular momentum of the fluid…

Astrophysics · Physics 2007-05-23 Chjan Lim

The explicit relationship is determined between the interior properties of a static cylindrical matter distribution and the metric of the exterior space-time according to Einstein gravity for space-time dimensionality larger or equal to…

General Relativity and Quantum Cosmology · Physics 2011-07-19 J. Colding , N. K. Nielsen , Y. Verbin

In this article, a special static spherically symmetric perfect fluid solution of Einstein's equations is provided. Though pressure and density both diverge at the origin, their ratio remains constant. The solution presented here fails to…

General Physics · Physics 2009-09-29 F. Rahaman , M. Kalam , S. Chakraborty , K. Maity , B. Raychaudhuri

A general formalism developed few years ago to model polytropic Newtonian stars with anisotropic pressure is applied to model stars for which, both, radial and tangential pressure satisfy polytropic equations of state. We obtain the…

General Relativity and Quantum Cosmology · Physics 2020-07-02 G. Abellan , E. Fuenmayor , L. Herrera

We present two methods for describing, from a pedagogical point of view, the solutions of Einstein's equations applied to a homogeneous and isotropic universe. In the first method, we define an effective gravitational potential of the…

Physics Education · Physics 2007-05-23 L. Arturo Ureña--López

We argue that an arbitrary general relativistic static anisotropic fluid sphere, (static and spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully mimicked by suitable linear…

General Relativity and Quantum Cosmology · Physics 2017-11-29 Petarpa Boonserm , Tritos Ngampitipan , Matt Visser

In this paper, we found new classes of solutions to the Einstein-Maxwell field equations with matter anisotropic distribution incorporating a particular form of electric field intensity within the framework of general relativity. We use a…

General Relativity and Quantum Cosmology · Physics 2023-10-03 Manuel Malaver , Rajan Iyer

The equations of state for a characteristic spacetime are studied in the context of the spherically symmetric interior exact and analytical solutions in Horava gravity and Einstein-aether theory in which anisotropic fluids are considered.…

General Relativity and Quantum Cosmology · Physics 2018-08-06 Daniele Vernieri

In this work we evaluate the physical acceptability of relativistic anisotropic spheres modeled by two polytropic equations of state -- with the same newtonian limit -- commonly used to describe compact objects in General Relativity. We…

General Relativity and Quantum Cosmology · Physics 2021-02-02 D. Suárez-Urango , L. A. Núñez , H. Hernández

We construct a toy model for isothermal spheres in Horava gravity, which includes Einstein's gravity if a parameter is appropriately chosen. The equations for the isothermal spheres are derived from the partition function of the gravitating…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Nahomi Kan , Kiyoshi Shiraishi

This paper examines the general formalism and applications of isotropic as well as anisotropic polytropic stars in curvature-matter coupled gravity. For this purpose, we consider static spherical and Schwarzschild spacetimes in the interior…

General Relativity and Quantum Cosmology · Physics 2022-02-16 M. Sharif , Amal Majid , M. Shafaqat

We study exact solutions of the Einstein-Maxwell equations for the interior gravitational field of static spherically symmetric charged compact spheres. The spheres consist of an anisotropic fluid with a charge distribution that gives rise…

General Relativity and Quantum Cosmology · Physics 2022-02-18 Krsna Dev

In the process of protostar formation, astrophysical gas clouds undergo thermodynamically irreversible processes and emit heat and radiation to their surroundings. Due the emission of this energy one can envision an idealized situation in…

General Relativity and Quantum Cosmology · Physics 2016-11-22 Mayer Humi , John Roumas