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We consider static spherically symmetric self-gravitating configurations of the perfect fluid within the framework of the torsion-based extended theory of gravity. In particular, we use the covariant formulation of $f(T)$ gravity with $f(T)…

General Relativity and Quantum Cosmology · Physics 2018-10-03 Sasa Ilijic , Marko Sossich

In this work, we develop a new relativistic model for a charged anisotropic compact star in the framework of modified symmetric teleparallel gravity, namely $f(Q)$-Euler-Heisenberg gravity. By employing the MIT bag model equation of state,…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Allah Ditta , M. Yousaf , G. Mustafa , S. K. Maurya , Farruh Atamurotov , Orhan Donmez , Sardor Murodov

The effects of the cosmological constant on the static equilibrium configurations and stability against small radial perturbations of relativistic polytropic spheres are investigated. This study numerically solves the hydrostatic…

General Relativity and Quantum Cosmology · Physics 2020-04-15 José D. V. Arbañil , Pedro H. R. S. Moraes

The hydrostatic equilibrium and the stability against radial perturbation of charged strange quark stars composed of a charged perfect fluid are studied. For this purpose, it is considered that the perfect fluid follows the MIT bag model…

Solar and Stellar Astrophysics · Physics 2017-06-30 José D. V. Arbañil , M. Malheiro

The dynamics of self-gravitating fluid bodies is described by the Euler-Einstein system of partial differential equations. The break-down of well-posedness on the fluid-vacuum interface remains a challenging open problem, which is…

General Relativity and Quantum Cosmology · Physics 2020-07-17 John Ryan Westernacher-Schneider , Charalampos Markakis , Bing Jyun Tsao

We investigate changes in Earth's atmospheric models coming from the $f(R,T)$ modified theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the stress-energy tensor.…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Taylor M. Ordines , Eric D. Carlson

Owed to their compactness, neutron stars involve strong gravity and extreme density physics. Nevertheless, at present, there are a variety of problems where progress (at least conceptually) can be made in the context of weak gravity.…

General Relativity and Quantum Cosmology · Physics 2023-03-02 Nils Andersson , Fabian Gittins , Shanshan Yin , Rodrigo Panosso Macedo

In this paper we will discuss charged stars with polytropic equation of state, where we will try to derive an equation analogous to the Lane-Emden equation. We will assume that these stars are spherically symmetric, and the electric field…

Astrophysics · Physics 2009-11-10 Rodrigo Picanco , Manuel Malheiro , Subharthi Ray

We use a modified Einstein-Maxwell gravity to study stability of an electrostatic spherical star. Correction terms in this model are scalers which are made from contraction of Ricci tensor and electromagnetic vector potential. Our…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Hossein Ghaffarnejad , Tohid Ghorbani , Firoozeh Eidizadeh

In the present paper we analyze and discuss some mathematical aspects of the fluid-static configurations of a self-gravitating perfect gas enclosed in a spherical solid shell. The mathematical model we consider is based on the well-known…

Based on a stringy inspired Gauss-Bonnet (GB) modification of classical gravity, we constructed a model for neutron stars. We derived the modified forms of Tolman-Oppenheimer-Volkoff (TOV) equations for a generic function of $f(G)$ gravity.…

General Relativity and Quantum Cosmology · Physics 2015-04-07 D. Momeni , R. Myrzakulov

Present investigation devoted to the dynamical study of Relativistic Hydrodynamics with some thermodynamical characteristics in $f(R,G)$ gravity towards spatially homogeneous isotropic cosmological model filled with isotropic fluid. We…

General Physics · Physics 2020-04-09 S. H. Shekh , Simran Arora , V. R. Chirde , P. K. Sahoo

We study Einstein static universes in the context of generic f(R) models. It is shown that Einstein static solutions exist for a wide variety of modified gravity models sourced by a barotropic perfect fluid with equation of state w=p/rho,…

General Relativity and Quantum Cosmology · Physics 2009-03-14 Sanjeev S. Seahra , Christian G. Boehmer

In this work we investigate neutron stars (NS) in $f(\mathcal{R,T})$ gravity for the case $R+2\lambda\mathcal{T}$, $\mathcal{R}$ is the Ricci scalar and $\mathcal{T}$ the trace of the energy-momentum tensor. The hydrostatic equilibrium…

High Energy Astrophysical Phenomena · Physics 2021-01-01 R. Lobato , O. Lourenço , P. H. R. S. Moraes , C. H. Lenzi , M. de Avellar , W. de Paula , M. Dutra , M. Malheiro

In this paper, we consider a spherical symmetric metric to extract the hydrostatic equilibrium equation of stars in $(3+1)-$dimensional gravity's rainbow in the presence of cosmological constant. Then, we generalize the hydrostatic…

High Energy Physics - Theory · Physics 2016-09-19 S. H. Hendi , G. H. Bordbar , B. Eslam Panah , S. Panahiyan

The possibility of modifications on general relativity is investigated. We propose an alternative theory of gravity constructed with the combination of Rastall and Rainbow theories. The hydrostatic equilibrium equations are obtained in…

High Energy Astrophysical Phenomena · Physics 2019-07-31 Clésio E. Mota , Luis C. N. Santos , Guilherme Grams , Franciele M. da Silva , Débora P. Menezes

We have designed and tested a new relativistic Lagrangian hydrodynamics code, which treats gravity in the conformally flat approximation to general relativity. We have tested the resulting code extensively, finding that it performs well for…

Astrophysics · Physics 2008-11-26 Joshua Faber , Philippe Grandclément , Frederic Rasio

In the metric approach of $f(R)$ theories of gravity, the fourth-order field equations are often recast as effective Einstein equations in the presence of standard matter and a curvature fluid (which gathers all the extra terms), always in…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis

Modeling the internal structure of self-gravitating solid and liquid bodies presents a challenge, as existing approaches are often limited to either overly simplistic constant-density approximations or more complex numerical equations of…

Earth and Planetary Astrophysics · Physics 2025-07-31 Bartosz Żbik , Andrzej Odrzywołek

This work aims to investigate some possible emergence of relativistic compact stellar objects in modified $f(\mathcal{G})$ gravity using Noether symmetry approach. For this purpose, we assume static spherically symmetric spacetime in the…

General Relativity and Quantum Cosmology · Physics 2020-06-08 M. Farasat Shamir , Tayyaba Naz