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Related papers: Tolman IV fluid sphere in bigravity

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The macroscopic properties of compact stars in modified gravity theories can be significantly different from the general relativistic (GR) predictions. Within the gravitational context of scalar-tensor theories, with a scalar field $\phi$…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis , Sergio B. Duarte , José D. V. Arbañil

Einstein's field equations with a background source term that induces perturbations and the applications of this new formalism to a compact dense matter relativistic star are presented. We introduce a new response kernel in the field…

High Energy Astrophysical Phenomena · Physics 2024-04-29 Seema Satin

We address the equilibrium configurations and stability properties of anisotropic compact stars whose interior is described by a modified Chaplygin gas (MCG) equation of state in the framework of the regularized four-dimensional…

General Relativity and Quantum Cosmology · Physics 2025-11-13 Anirudh Pradhan , Takol Tangphati , Ayan Banerjee , Javlon Rayimbaev

Some theorems for a static prefect fluid sphere, i.e. a star, in the presence of a positive cosmological constant are proved. These theorems put bounds on the pressure profile and internal compactness of the star.

General Relativity and Quantum Cosmology · Physics 2014-02-05 F. Shojai , A. Shojai , M. Mousavi

String theory has no parameter except the string scale, so a dynamically compactified solution to 4 dimensional spacetime should determine both the Planck scale and the cosmological constant $\Lambda$. In the racetrack K\"ahler uplift flux…

High Energy Physics - Theory · Physics 2019-10-25 Stefano Andriolo , Shing Yan Li , S. H. Henry Tye

In this paper, we studied the behavior of relativistic objects with anisotropic matter distribution considering Tolman IV form for the gravitational potential Z. The equation of state presents a quadratic relation between the energy density…

General Physics · Physics 2015-03-29 Manuel Malaver

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

In this work, we investigate an anisotropic compact star's physical properties and stability in F(Q) gravity. The study focuses on the significance of F(Q) gravity on the structure and stability of compact star, considering non-perfect…

General Relativity and Quantum Cosmology · Physics 2024-09-26 Sat Paul , Jitendra Kumar , Sunil Kumar Maurya , Sourav Choudhary , Sweeti Kiroriwala

By employing four typical equation of states (EOSs) of the inner crust matters, the constraint on properties of low-mass neutron stars are theoretically investigated. Based on the well known fact that there is a big gap between the neutron…

High Energy Astrophysical Phenomena · Physics 2017-07-05 Yongmei Wen , Dehua Wen

We consider the Einstein flow on a product manifold with one factor being a compact quotient of 3-dimensional hyperbolic space without boundary and the other factor being a flat torus of fixed arbitrary dimension. We consider initial data…

Mathematical Physics · Physics 2019-03-01 Volker Branding , David Fajman , Klaus Kroencke

A stability criterion is derived in general relativity for self-similar solutions with a scalar field and those with a stiff fluid, which is a perfect fluid with the equation of state $P=\rho$. A wide class of self-similar solutions turn…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Tomohiro Harada , Hideki Maeda

Temporal and spatial variation of fine-structure constant $\alpha\equiv e^2/\hbar c$ in cosmology has been reported in analysis of combination Keck and VLT data. This paper studies this variation based on consideration of basic spacetime…

General Relativity and Quantum Cosmology · Physics 2015-09-02 Sze-Shiang Feng , Mu-Lin Yan

Although the interpretation of complexity in extended theories of gravity is available in the literature, its illustration in $f(R,L_{m},\mathcal{T})$ theory is still ambiguous. The orthogonal decomposition of the Riemann tensor results in…

General Relativity and Quantum Cosmology · Physics 2025-06-23 A. Rehman , Tayyab Naseer , Nazek Alessa , Abdel-Haleem Abdel-Aty

This paper presents the class of solutions to the Einstein field equations for the uncharged static spherically symmetric compact object PSR J0952-0607 by using Generalized Tolman-Kuchowicz space-time metric with quadratic equation of…

General Relativity and Quantum Cosmology · Physics 2025-04-04 Hemani R. Acharya , D. M. Pandya , Bharat Parekh , V. O. Thomas

This paper is devoted to explore some relativistic configurations of stellar objects for static spherically symmetric structures in the context of modified $f(\mathcal{G})$ gravity, by exploiting the Tolman-Kuchowicz spacetime [1,2]. We…

General Relativity and Quantum Cosmology · Physics 2020-01-23 M. Farasat Shamir , Tayyaba Naz

The acceleration parameter defined through the local volume expansion is negative for a pressureless, irrotational fluid with positive energy density. In the presence of inhomogeneities or anisotropies the volume expansion rate results from…

Present paper provides a model of static charged anisotropic fluid sphere in the EinsteinMaxwell- GaussBonnet (EMGB) theory of gravitation. We select KB anstz as the metric co-efficient along with electric field intensity. To develop our…

General Physics · Physics 2021-04-13 Piyali Bhar , Megan Govender

We investigate a compact spherically symmetric relativistic body with anisotropic particle pressure profiles. The distribution possesses characteristics relevant to modeling compact stars within the framework of general relativity. For this…

General Relativity and Quantum Cosmology · Physics 2018-02-28 S. K. Maurya , Ayan Banerjee , Sudan Hansraj

In recent years, a growing interest on the equilibrium of compact astrophysical objects like white dwarf and neutron stars has been manifested. In particular, various modifications due to Planck scale energy effects have been considered. In…

General Relativity and Quantum Cosmology · Physics 2017-03-08 Remo Garattini , Gianluca Mandanici

We consider static charged fluid spheres with a cosmological constant. We assume a polytropic equation of state, $p \propto \rho^\Gamma$, and a power law charge distribution, $q\propto r^n$. Using this, we convert the generalised…

General Relativity and Quantum Cosmology · Physics 2026-03-30 Alex Stornelli , Anish Agashe
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