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Related papers: Collapsing spherical stars in f(R) gravity

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In this article we try to present spherically symmetric isotropic strange star model under the framework of $f(R,\mathcal{T})$ theory of gravity. To this end, we consider that the Lagrangian density is an arbitrary linear function of the…

General Relativity and Quantum Cosmology · Physics 2018-04-23 Debabrata Deb , Farook Rahaman , Saibal Ray , B. K. Guha

One of the possible potential candidates for describing the universe's rapid expansion is modified gravity. In the framework of the modified theory of gravity $f(R,G)$, the present work features the materialization of anisotropic matter,…

General Relativity and Quantum Cosmology · Physics 2022-06-29 W. U. Rahman , M. Ilyas , Z. Yousaf , S. Ullah , F. Khan , R. khan

In the present work, gravitational collapse of an inhomogeneous spherical star model, consisting of inhomogeneous dust fluid (dark matter) in the background of dark energy is considered. The collapsing process is examined first separately…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Tanwi Bandyopadhyay , Subenoy Chakraborty

Scalar-tensor~(ST) theories of gravity are natural phenomenological extensions to general relativity. Although these theories are severely constrained both by solar system experiments and by binary pulsar observations, a large set of ST…

General Relativity and Quantum Cosmology · Physics 2016-02-10 Carlos Palenzuela , Steve Liebling

We study the implications of $R^n$ extension of Starobinsky model on dynamical instability of Vorticity-free axially symmetric gravitating body. The matter distribution is considered to be anisotropic for which modified field equations are…

General Relativity and Quantum Cosmology · Physics 2015-04-13 Ifra Noureen , Abdul Aziz Bhatti , M. Zubair

All $f(R)$ modified gravity theories are conformally identical to models of quintessence in which matter is coupled to dark energy with a strong coupling. This coupling induces a cosmological evolution radically different from standard…

Astrophysics · Physics 2008-11-26 Luca Amendola , David Polarski , Shinji Tsujikawa

Using a perturbative approach we solve stellar structure equations for low-density (solar-type) stars whose interior is described with a polytropic equation of state in scenarios involving a subset of modified gravity theories. Rather than…

Solar and Stellar Astrophysics · Physics 2019-02-27 M. Cermeño , J. Carro , A. L. Maroto , M. Ángeles Pérez-García

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

Current study highlights the physical characteristics of charged anisotropic compact stars by exploring some exact solutions of modified field equations in $f(R,G)$ gravity. A comprehensive analysis is performed from the obtained solutions…

General Relativity and Quantum Cosmology · Physics 2018-06-13 M. Farasat Shamir , Saeeda Zia

We study the impact of non-local modifications of General Relativity on stellar structure. In particular, assuming an analytic distortion function and specific equations of state, we made use of remnant stars to put qualitative constraints…

General Relativity and Quantum Cosmology · Physics 2023-01-23 Grigoris Panotopoulos , Javier Rubio , Ilídio Lopes

The kinetic motion of the stars of a galaxy is considered within the framework of a relativistic scalar theory of gravitation. This model, even though unphysical, may represent a good laboratory where to study in a rigorous, mathematical…

Mathematical Physics · Physics 2017-08-23 Simone Calogero

Modifications to gravity that add additional functions of the Ricci curvature to the Einstein-Hilbert action -- collectively known as $f(R)$ theories -- have been studied in great detail. When considered as complete theories of gravity they…

Astrophysics · Physics 2009-02-20 Simon DeDeo , Dimitrios Psaltis

In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas

In this paper we study scalar perturbations of the metric for nonlinear $f(R)$ models. We consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. We investigate the astrophysical approach in the case…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Maxim Eingorn , Jan Novák , Alexander Zhuk

Gravitational collapse of a class of spherically symmetric stars are investigated. We quantise the geometries describing the gravitational collapse by a deformation quantisation procedure. This gives rise to noncommutative spacetimes with…

High Energy Physics - Theory · Physics 2011-02-09 Wen Sun , Ding Wang , Naqing Xie , R. B. Zhang , Xiao Zhang

This paper's main aim is to investigate the existence of a new classification of embedded class-I solutions of compact stars, by using Karmarkar condition in $f(R)$ gravity background. To achieve that goal, we consider two different models…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Tayyaba Naz , Ammara Usman , M. Farasat Shamir

In the present work we study strange stars in $f(R)$ theories of gravity in the Palatini formalism. We consider two concrete well-known cases, namely the $R+R^2/(6 M^2)$ model as well as the $R-\mu^4/R$ model for two different values of the…

General Relativity and Quantum Cosmology · Physics 2017-05-03 Grigoris Panotopoulos

The present analytical understanding on the nature of the singularities which form at the endstate of gravitational collapse of massive fluid bodies ("stars") is reviewed. Special emphasis is devoted to the issue of physical reasonability…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sanjay Jhingan , Giulio Magli

The main emphasis of this paper is to find the viable solutions of Einstein Maxwell fields equations of compact star in context of modified $f(R)$ theory of gravity. Two different models of modified $f(R)$ gravity are considered. In…

General Relativity and Quantum Cosmology · Physics 2023-05-16 M. Farasat Shamir , Aisha Rashid

We have found some new exact static spherically symmetric interior solutions of metric $f(R)$ gravitational theories describing the equilibrium configuration of a star. Then the solution is matched to the exterior solution and thus gives a…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Ali Shojai , Fatimah Shojai
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