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Related papers: Gravitationally collapsing stars in $f(R)$ gravity

200 papers

We study the collapse of a self-gravitating and radiating shell. Matter constituting the shell is quantized and the construction is viewed as a semiclassical model of possible black hole formation. It is shown that the shell internal…

General Relativity and Quantum Cosmology · Physics 2008-11-26 G. L. Alberghi , R. Casadio , G. P. Vacca , G. Venturi

An outstanding problem in gravitation theory and relativistic astrophysics today is to understand the final outcome of an endless gravitational collapse. Such a continual collapse would take place when stars more massive than few times the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Pankaj S. Joshi

The process of gravitational collapse excites the fields propagating in the background geometry and gives rise to thermal radiation. We demonstrate by explicit calculations that the density matrix corresponding to such radiation actually…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Anshul Saini , Dejan Stojkovic

Using the Sparling form and a geometric construction adapted to spacetimes with a 2-dimensional isometry group, we analyse a quasi-local measure of gravitational energy. We then study the gravitational radiation through spacetime junctions…

General Relativity and Quantum Cosmology · Physics 2018-11-27 Alfonso García-Parrado , Filipe C. Mena

According to conventional modelling by general relativity the collapse of radially symmetric gravitating objects may end in a singular state. But by inclusion of potential energy into the energy tensor, which is required to guarantee global…

General Physics · Physics 2013-03-27 Ernst Fischer

Gravity and thermal energy are universal phenomena which compete over the stabilization of astrophysical systems. The former induces an inward pressure driving collapse and the latter a stabilizing outward pressure generated by random…

General Relativity and Quantum Cosmology · Physics 2020-12-21 Zacharias Roupas

We investigate the gravitational collapse of a spherically symmetric, inhomogeneous star, which is described by a perfect fluid with heat flow and satisfies the equation of state $p=\rho/3$ or $p=C\rho^\ga$ at its center. Different from the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Zhe Chang , Cheng-Bo Guan , Chao-Guang Huang , Xin Li

In this paper we work out collapsing conditions for a spherical star in the weak field limit of the $R+\mu^4/R$ gravity and discuss the importance of the parameter $\mu$ to generate different criteria in the theory. Such criteria are proved…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Mohsen Fathi , Morteza Mohseni

This thesis aims at improving our understanding of the strong-field regime of gravity, where deviations from General Relativity (GR) are expected to be found on theoretical grounds. In particular, we have been concerned with the formulation…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Adrián Casado-Turrión

We investigate a curvature singularity appearing in the star collapse process in $F(R)$ gravity. In particular, we propose an understanding of the mechanism to produce the curvature singularity. Moreover, we explicitly demonstrate that…

General Relativity and Quantum Cosmology · Physics 2011-04-20 Kazuharu Bamba , Shin'ichi Nojiri , Sergei D. Odintsov

This paper is about the $n+2$-dimensional gravitational contraction of inhomogeneous fluid without heat flux in the framework of $f(R)$ metric theory of gravity. Matching conditions for two regions of a star has been derived by using the…

General Relativity and Quantum Cosmology · Physics 2017-08-02 G. Abbas , M. S. Khan , Zahid Ahmad , M. Zubair

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

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

We use 1-dimensional numerical simulations to study spherical collapse in the f(R) gravity models. We include the nonlinear coupling of the gravitational potential to the scalar field in the theory and use a relaxation scheme to follow the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Alex Borisov , Bhuvnesh Jain , Pengjie Zhang

We investigate the collapse of a circularly symmetric star with outgoing radiation in ($2+1$)-dimensional anti-de Sitter spacetime. The exterior spacetime of the collapsing star is assumed to be described by the non-static generalization of…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Ranjan Sharma , Shyam Das , Farook Rahaman , Gopal Chandra Shit

In this work, we explore the eternal collapsing phenomenon of a stellar system (e.g., a star) within the framework of $f(R)$ gravity and investigate some new aspects of the continued homogeneous gravitational collapse with perfect fluid…

General Relativity and Quantum Cosmology · Physics 2023-11-30 Annu Jaiswal , Rajesh Kumar , Sudhir Kumar Srivastava , Megandhren Govender

The gravitational collapse of a star is a warmly discussed but still puzzling problem, which not only involves the dynamics of the gases, but also the subtle coordinate transformation. In this letter, we give some more detailed…

General Relativity and Quantum Cosmology · Physics 2009-04-30 Ying-Qiu Gu

This article examines the dynamics of gravitational collapse in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ gravity, where $\mathcal{Q}=\mathcal{R}_{\mathrm{ab}}\mathcal{T}^{\mathrm{ab}}$. We consider self-gravitating anisotropic cylindrical…

General Relativity and Quantum Cosmology · Physics 2024-02-06 M. Sharif , Tayyab Naseer

It is now known that when a massive star collapses under the force of its own gravity, the final fate of such a continual gravitational collapse will be either a black hole or a naked singularity under a wide variety of physically…

General Relativity and Quantum Cosmology · Physics 2012-04-20 Pankaj S. Joshi , Daniele Malafarina

We will make a comparison between the dynamics of spherical gravitational collapse for a perturbed FLRW universe to first order in the context of general relativity, with the corresponding results obtained for the gravitational collapse…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-12 César Peralta , Leonardo Castañeda