English
Related papers

Related papers: Viscous Chaplygin Gas Models as a Spherical Top-Ha…

200 papers

In this paper, we reconstruct various solutions for the accelerated universe in the Einstein-Aether theory of gravity. For this purpose, we obtain the effective density and pressure for Einstein-Aether theory. We reconstruct the…

General Physics · Physics 2019-07-23 Shamaila Rani , Abdul Jawad , Kazuharu Bamba , Irfan Ullah Malik

The collapse of marginally bound, inhomogeneous, pressureless (dust) matter, in spherical symmetry, is considered. The starting point is not, in this case, the integration of the Einstein equations from some suitable initial conditions.…

General Relativity and Quantum Cosmology · Physics 2018-04-27 Ramon Lapiedra , Juan Antonio Morales-Lladosa

In this work, we study the Friedmann-Robertson-Walker cosmology in which a Chaplygin gas is coupled to a non-linear scalar field in the framework of the Ho\v{r}ava-Lifshitz theory. In writing the action of the matter part, we use the…

General Relativity and Quantum Cosmology · Physics 2017-06-27 H. Ardehali , P. Pedram , B. Vakili

In this work, we have considered the Friedmann-Robertson-Walker (FRW) model of the universe where bounce occurs and the universe is filled with Generalized Cosmic Chaplygin Gas (GCCG) or Variable Modified Chaplygin Gas (VMCG). We have…

General Relativity and Quantum Cosmology · Physics 2018-12-11 Tanwi Bandyopadhyay , Ujjal Debnath

To systematically analyze the dynamical implications of the matter content in cosmology, we generalize earlier dynamical systems approaches so that perfect fluids with a general barotropic equation of state can be treated. We focus on…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. Mark Heinzle , N. Rohr , C. Uggla

The turnaround epoch of gravitational collapse is examined by means of relativistic Lagrangian perturbation theory. Averaged, scalar equations applied to the fluid's evolution reveal some scale-independent universality of parameters for a…

General Relativity and Quantum Cosmology · Physics 2020-01-01 Jan J. Ostrowski

We consider the gravitational collapse of a spherically symmetric homogeneous matter distribution consisting of a Weyssenhoff fluid in the presence of a negative cosmological constant. Our aim is to investigate the effects of torsion and…

General Relativity and Quantum Cosmology · Physics 2017-04-19 Amir Hadi Ziaie , Paulo Vargas Moniz , Arash Ranjbar , Hamid Reza Sepangi

We investigate the effects of viscosity terms depending on the Hubble parameter and its derivatives in the dark energy equation of state. Such terms are possible if dark energy is a fictitious fluid originating from corrections to the…

Astrophysics · Physics 2010-04-06 S. Capozziello , V. F. Cardone , E. Elizalde , S. Nojiri , S. D. Odintsov

In this work the collapsing process of a spherically symmetric star, made of dust cloud, in the background of dark energy is studied for two different gravity theories separately, i.e., DGP Brane gravity and Loop Quantum gravity. Two types…

General Physics · Physics 2015-06-04 Prabir Rudra , Ritabrata Biswas , Ujjal Debnath

We study the hydrodynamic limit of the Chern--Simons--Higgs system, a relativistic gauge field model involving the Chern--Simons interaction. We introduce a single scaling parameter capturing both the non-relativistic (infinite speed of…

Analysis of PDEs · Mathematics 2026-04-10 Jeongho Kim , Bora Moon

We consider a double polytropic cosmological fluid and demonstrate that, when one constituent resembles a bare cosmological constant while the other emulates a generalized Chaplygin gas, a good description of the Universe's large-scale…

General Relativity and Quantum Cosmology · Physics 2024-03-27 Peter K. S. Dunsby , Orlando Luongo , Marco Muccino , Vineshree Pillay

We study blackhole in the Modified Generalized Chaplygin Gas (MGCG) model, a modified gravity framework proposed to unify dark matter and dark energy. The resulting spacetime is asymptotically non-flat and feature two distinct horizons,…

General Relativity and Quantum Cosmology · Physics 2026-03-25 Sunil Singh Bohra

We study the evolution of inhomogeneous spherical perturbations in the universe in a way that generalizes the spherical top hat collapse in a straightforward manner. For that purpose we derive a dynamical equation for the evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-13 T. S. Pereira , R. Rosenfeld , A. Sanoja

A flat FLRW cosmological model with perfect fluid comprising of variable Chaplygin gas has been studied in context of f(R; T) gravity with particle creation. The considered scale factors describe the accelerated expansion of universe due to…

General Relativity and Quantum Cosmology · Physics 2020-02-12 N. Hulke , G. P. Singh , Binaya K. Bishi , A. Singh

In this note two cosmological models representing the flat Friedmann Universe filled with a Chaplygin fluid, with or without dust, are analyzed in terms of the recently proposed "statefinder" parameters. Trajectories of both models in the…

Astrophysics · Physics 2009-11-07 Vittorio Gorini , Alexander Kamenshchik , Ugo Moschella

We present a reformulation of loop quantum gravity with a cosmological constant and no matter as a Fermi-liquid theory. When the topological sector is deformed and large gauge symmetry is broken, we show that the Chern-Simons state reduces…

High Energy Physics - Theory · Physics 2008-12-18 Stephon H. S. Alexander , Gianluca Calcagni

We extend the equation of state of GCG (Generalized Chaplygin Gas) to $w<-1$ regime and show, from the point of view of dynamics, that the parameters of GCG should be in the range of $0<\alpha<1$. Also, dynamical analysis indicate that the…

Astrophysics · Physics 2009-11-10 Jian-gang Hao , Xin-zhou Li

We investigate the thermodynamical and causal consistency of cosmological models of the cubic Quasi-Topological Gravity (QTG) in four dimensions, as well as their phenomenological consequences. Specific restrictions on the maximal values of…

General Relativity and Quantum Cosmology · Physics 2013-04-16 U. Camara dS , A. A. Lima , G. M. Sotkov

The Einstein field equation as an equation of state of a thermodynamical system of spacetime is reconsidered in the present Letter. We argue that a consistent interpretation leads us to identify scalar curvature and cosmological constant…

General Relativity and Quantum Cosmology · Physics 2007-05-29 S. C. Tiwari

We explore the gravitational collapse of a spherically symmetric dust cloud in the Einstein-Gauss-Bonnet gravity without a cosmological constant, and obtain three families of LTB-like solutions. It is shown that the Gauss-Bonnet term has a…

General Relativity and Quantum Cosmology · Physics 2011-10-04 Kang Zhou , Zhan-Ying Yang , De-Cheng Zou , Rui-Hong Yue