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Related papers: Modeling usual and unusual anisotropic spheres

200 papers

We attempt to study a singularity-free model for the spherically symmetric anisotropic strange stars under Einstein's general theory of relativity by exploiting the Tolman-Kuchowicz metric. Further, we have assumed that the cosmological…

General Relativity and Quantum Cosmology · Physics 2018-10-03 M. K. Jasim , Debabrata Deb , Saibal Ray , Y. K. Gupta , Sourav Roy Chowdhury

The condition for the vanishing of the Weyl tensor is integrated in the spherically symmetric case. Then, the resulting expression is used to find new, conformally flat, interior solutions to Einstein equations for locally anisotropic…

General Relativity and Quantum Cosmology · Physics 2015-06-25 L. Herrera , A. Di Prisco , J. Ospino , E. Fuenmayor

The first static spherically symmetric perfect fluid solution with constant density was found by Schwarzschild in 1918. Generically, perfect fluid spheres are interesting because they are first approximations to any attempt at building a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Petarpa Boonserm , Matt Visser , Silke Weinfurtner

We consider an anisotropic version of Baxter's model of `sticky hard spheres', where a nonuniform adhesion is implemented by adding, to an isotropic surface attraction, an appropriate `dipolar sticky' correction (positive or negative,…

Soft Condensed Matter · Physics 2009-11-13 Domenico Gazzillo , Riccardo Fantoni , Achille Giacometti

We explore gravitating relativistic spheres composed of an anisotropic, barotropic uid. We assume a bi-polytropic equation of state which has a linear and a power-law terms. The generalized Tolman-Oppenheimer-Volkoff (TOV) equation which…

General Relativity and Quantum Cosmology · Physics 2016-11-03 Nematollah Riazi , S. Sedigheh Hashemi , S. Naseh Sajadi , S. Shahrokh Assyaee

The semi-review paper studies the null geodesics which appear for black hole solutions in the gravitational $4d$ model with anisotropic fluid. The equations of state for the fluid and solutions itselves depend upon integer parameter $q = 1,…

General Relativity and Quantum Cosmology · Physics 2025-09-11 V. D. Ivashchuk , S. V. Bolokhov , F. B. Belissarova , N. Kydyrbay , A. N. Malybayev , G. S. Nurbakova , B. Zheng

We investigate static spherically symmetric perfect fluid models in Newtonian gravity for barotropic equations of state that are asymptotically polytropic at low and high pressures. This is done by casting the equations into a 3-dimensional…

Astrophysics · Physics 2009-11-07 J. Mark Heinzle , Claes Uggla

We present a spherically symmetric solution of the general relativistic field equations in isotropic coordinates for charged fluid with pressure anisotropy, compatible with a super dense star modeling. Further, we have constructed an…

General Physics · Physics 2015-02-12 Ksh. Newton Singh , Narendra Pradhan , Manuel Malaver

It is shown that unlike the perfect fluid case, anisotropic fluids (principal stresses unequal) may be geodesic, without this implying the vanishing of (spatial) pressure gradients. Then the condition of vanishing four acceleration is…

General Relativity and Quantum Cosmology · Physics 2009-11-07 L. Herrera , J. Martin , J. Ospino

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

Starting with any stationary axisymmetric vacuum metric, we build anisotropic fluids. With the help of the Ernst method, the basic equations are derived together with the expression for the energy-momentum tensor and with the equation of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Stefano Viaggiu

In this work we will analyse the complexity factor, proposed by L. Herrera, for spherically symmetric static matter distributions satisfying a polytropic equation through the gravitational decoupling method. Specifically, we will use the…

General Relativity and Quantum Cosmology · Physics 2022-11-04 C. Las Heras , P. Leon

We provide a new class of interior solutions for anisotropic stars admitting conformal motion. The Einstein's field equations in this construction are solved for specific choices of the density/mass functions. We analyze the behavior of the…

General Relativity and Quantum Cosmology · Physics 2010-11-03 Farook Rahaman , Mubasher Jamil , Ranjan Sharma , Kausik Chakraborty

In this work, we construct stellar models ba-\break sed on the complexity factor as a supplementary condition which allows to close the system of differential equations arising from the Gravitational Decoupling. The assumed complexity is a…

General Relativity and Quantum Cosmology · Physics 2021-10-20 J. Andrade , E. Contreras

We investigate spherically symmetric cosmological models in Einstein-aether theory with a tilted (non-comoving) perfect fluid source. We use a 1+3 frame formalism and adopt the comoving aether gauge to derive the evolution equations, which…

General Relativity and Quantum Cosmology · Physics 2015-12-08 Alan A. Coley , Genly Leon , Patrik Sandin , Joey Latta

We find a reconstruction algorithm able to generate all the static spherically symmetric interior solutions in the framework of Ho\v{r}ava gravity and Einstein-\ae ther theory in presence of anisotropic fluids. We focus for simplicity on…

General Relativity and Quantum Cosmology · Physics 2018-04-10 Daniele Vernieri , Sante Carloni

We start with a recently introduced spherically symmetric geodesic fluid model (arXiv: 1601.07030) whose energy-momentum tensor in the comoving frame is dust-like with nontrivial energy flux. In the non-comoving energy frame (vanishing…

General Physics · Physics 2018-02-14 Peter C. Stichel

The paper is concerned with the Einstein equations for a spherically symmetric static distribution of anisotropic matter. The equations are cast into a system of Fuchsian type ODE for certain scalar invariants of the strain. And then the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Jiseong Park

In this paper, we have studied gravitational collapse and expansion of non-static anisotropic fluid in $5D$ Einstein Gauss-Bonnet gravity. For this purpose, the field equations have been modeled and evaluated for the given source and…

General Relativity and Quantum Cosmology · Physics 2018-12-19 G. Abbas , M. Tahir

Our manuscript aims to analysis the viability and stability of anisotropic stellar objects in the modified symmetric teleparallel gravity. A particular model of this extended theory is considered to formulate explicit field equations which…

General Relativity and Quantum Cosmology · Physics 2024-08-29 M. Zeeshan Gul , M. Sharif , Adeeba Arooj