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Related papers: Buchdahl model in f(R, T) gravity: A comparative s…

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We consider interior static and spherically symmetric solutions in a gravity theory that extends the standard Hilbert-Einstein action with a Lagrangian constructed from a three-form field $A_{\alpha \beta \gamma}$, which generates, via the…

General Relativity and Quantum Cosmology · Physics 2021-04-14 Bruno J. Barros , Zahra Haghani , Tiberiu Harko , Francisco S. N. Lobo

We study generalizations of Buchdahl's compactness limits for perfect-fluid star solutions of $D$-dimensional Einstein gravity coupled to higher-curvature corrections. We focus on Quasi-topological theories involving infinite towers of…

General Relativity and Quantum Cosmology · Physics 2026-03-27 Pablo Bueno , Robie A. Hennigar , Ángel J. Murcia , Aitor Vicente-Cano

Utilizing various gauges of the radial coordinate we give a description of static spherically symmetric space-times with point singularity at the center and vacuum outside the singularity. We show that in general relativity (GR) there exist…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Plamen Fiziev

A class of $f(R, T)$ theories extends the Einstein-Hilbert action by incorporating a general function of $R$ and $T$, the Ricci scalar and the trace of the ordinary energy-momentum tensor $T_{\mu\nu}$, respectively, thereby introducing a…

General Relativity and Quantum Cosmology · Physics 2025-07-30 Yaghoub Heydarzade , Maryam Ranjbar

We investigate stability of the Einstein static solution against homogeneous scalar, vector and tensor perturbations in the context of Rastall theory of gravity. We show that this solution in the presence of perfect fluid and vacuum energy…

General Relativity and Quantum Cosmology · Physics 2018-07-10 F. Darabi , K. Atazadeh , Y. Heydarzade

We obtain a class of anisotropic spherically symmetric relativistic solutions of compact objects in hydrostatic equilibrium in the $f(R,T) =R+2\chi T$ modified gravity, where $R$ is the Ricci scalar, $T$ is the trace of the energy momentum…

General Physics · Physics 2020-09-18 S. Dey , A. Chanda , B. C. Paul

The basic aim of this manuscript is to investigate the cosmological solutions in the context of the modified $f(R, T)$ theory of gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor. For our current…

General Relativity and Quantum Cosmology · Physics 2024-03-26 Adnan Malik , Tayyaba Naz , Aimen Rauf , M. Farasat Shamir , Z. Yousaf

This paper is devoted to investigate the exact solutions of Bianchi type $I$ spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an arbitrary function of Ricci scalar $R$ and trace of the energy momentum tensor $T$. For this…

General Relativity and Quantum Cosmology · Physics 2015-06-30 M. Farasat Shamir

Utilizing various gauges of the radial coordinate we give a description of static spherically symmetric space-times with point singularity at the center and vacuum outside the singularity. We show that in general relativity (GR) there exist…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Plamen Fiziev

We construct equilibrium configurations for neutron stars using a specific $f(R,T)$ functional form, recently derived through gaussian process applied to measurements of the Hubble parameter. By construction, this functional form serves as…

General Relativity and Quantum Cosmology · Physics 2024-11-15 J. T. Quartuccio , P. H. R. S. Moraes , G. N. Zeminiani , M. M. Lapola

Spherically symmetric anisotropic static compact solutions to the Einstein equations in dimension $d\geq4$ are considered. Various matter models are examined and upper bounds on the ratio of the gravitational mass to the radius in these…

General Relativity and Quantum Cosmology · Physics 2015-10-09 Matthew Wright

We consider the Palatini formulation of $f(R,T)$ gravity theory, in which a nonminimal coupling between the Ricci scalar and the trace of the energy-momentum tensor is introduced, by considering the metric and the affine connection as…

General Relativity and Quantum Cosmology · Physics 2018-07-24 Jimin Wu , Guangjie Li , Tiberiu Harko , Shi-Dong Liang

Hybrid metric-Palatini gravity is a recent and novel approach to modified theories of gravity, which consists of adding to the metric Einstein-Hilbert Lagrangian an f(R) term constructed a la Palatini. It was shown that the theory passes…

General Relativity and Quantum Cosmology · Physics 2015-02-19 Christian G. Boehmer , Francisco S. N. Lobo , Nicola Tamanini

We generalise the Buchdahl-Bondi limit for the case of static, spherically symmetric, relativistic compact stars immersed in Schwarzschild vacuum in f(R)-theory of gravity, subject to very generic regularity, thermodynamic stability and…

General Relativity and Quantum Cosmology · Physics 2015-09-09 Rituparno Goswami , Sunil D. Maharaj , Anne Marie Nzioki

Recently, the scalar-tensor representation of $f (R,T)$ gravity was used to explore gravitationally induced particle production/annihilation. Using the framework of irreversible thermodynamics of open systems in the presence of matter…

General Relativity and Quantum Cosmology · Physics 2023-10-20 Amine Bouali , Himanshu Chaudhary , Tiberiu Harko , Francisco S. N. Lobo , Taoufik Ouali , Miguel A. S. Pinto

This study explores singularity-free solutions to the static, spherical symmetric Einstein equations with the standard Schwarzschild solution as a boundary condition. Imposing the absence of curvature singularities and requiring…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Sune Rastad Bahn , Michael Cramer Andersen

We show that it is possible to obtain a picture of equilibrium thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density $f(R, \phi, X)$, where…

General Relativity and Quantum Cosmology · Physics 2010-10-12 Kazuharu Bamba , Chao-Qiang Geng , Shinji Tsujikawa

This paper has been withdrawn by the author after further work showed the proposed theoretical approach cannot fit planetary perihelion precession data. As presented, the theory doesn't fit gravitational light deflection by the sun either,…

General Physics · Physics 2014-03-28 Steven Kenneth Kauffmann

Teleparallel Gravity offers the possibility of reformulating gravity in terms of torsion by exchanging the Levi-Civita connection with the Weitzenb\"ock connection which describes torsion rather than curvature. Surprisingly, Teleparallel…

General Relativity and Quantum Cosmology · Physics 2020-07-23 Maria Caruana , Gabriel Farrugia , Jackson Levi Said

We consider cosmological scenarios based on $f(R,T)$ theories of gravity ($R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor) and numerically reconstruct the function $f(R,T)$ which is able to reproduce the same…

General Relativity and Quantum Cosmology · Physics 2015-03-19 M. J. S. Houndjo , Oliver F. Piattella