English
Related papers

Related papers: Generalized Chaplygin Gas in a modified gravity ap…

200 papers

In this work, we explore the cosmological dynamics of a modified gravity framework based on the function $f(Q,B)=\delta Q^{2}+\beta B$, where $Q$ denotes the nonmetricity scalar and $B$ is the boundary term that relates $Q$ to the Ricci…

General Relativity and Quantum Cosmology · Physics 2025-07-22 Amit Samaddar , S. Surendra Singh

In this paper we study FRW bulk viscous cosmology in presence of modified Chaplygin gas. We write modified Friedmann equations due to bulk viscosity and Chaplygin gas and obtain time-dependent energy density for the special case of flat…

General Physics · Physics 2016-12-02 H. Saadat , B. Pourhassan

We study the nonlinear regime of Unified Dark Energy models, using Generalized Chaplygin Gas cosmologies as a representative example, and introduce a new parameter characterizing the level of small scale clustering in these scenarios. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 P. P. Avelino , K. Bolejko , G. F. Lewis

A modified gravitational theory explains early universe and late time cosmology, galaxy and galaxy cluster dynamics. The modified gravity (MOG) theory extends general relativity (GR) by three extra degrees of freedom: a scalar field $G$,…

General Relativity and Quantum Cosmology · Physics 2020-10-30 J. W. Moffat

The reconstruction scheme is developed for modified $f(R)$ gravity with realistic matter (dark matter, baryons, radiation). Two versions of such theory are constructed: the first one describes the sequence of radiation and matter…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

In this work we investigate the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by Einstein-Aether gravity. Dark energy in the form of Modified Chaplygin gas is…

General Physics · Physics 2014-08-21 Chayan Ranjit , Prabir Rudra , Sujata Kundu

We consider a model of the Universe with variable G and {\Lambda}. Subject of our interest is a phenomenological model for {\Lambda} proposed and considered in this article first time (up to our knowledge). Modification based on an…

General Relativity and Quantum Cosmology · Physics 2015-01-13 M. Khurshudyan , J. Sadeghi , E. Chubaryan , H. Farahani

We consider general curvature-invariant modifications of the Einstein-Hilbert action that become important only in regions of extremely low space-time curvature. We investigate the far future evolution of the universe in such models,…

Globular clusters (GCs) in the Milky Way have characteristic velocity dispersions that are consistent with the predictions of Newtonian gravity, and may be at odds with Modified Newtonian Dynamics (MOND). We discuss a modified gravity (MOG)…

Astrophysics · Physics 2008-06-14 J. W. Moffat , V. T. Toth

We consider the effect of modified gravity on the growth of large-scale structures at second order in perturbation theory. We show that modified gravity models changing the linear growth rate of fluctuations are also bound to change,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Francis Bernardeau , Philippe Brax

In this paper, we continue our previous work of studying viscous generalized Chaplygin gas (VGCG) as a unified dark fluid but including the bulk viscosity perturbation. By using the currently available cosmic observational data from SNLS3,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-03 Wei Li , Lixin Xu

New corrections to General Relativity are considered in the context of modified $f(R)$ gravity, that satisfy cosmological and local gravity constraints. The proposed models behave asymptotically as $R-2\Lambda$ at large curvature and show…

General Relativity and Quantum Cosmology · Physics 2022-01-13 L. N. Granda

Many theories of modified gravity, including the well studied Horndeski models, are characterized by a screening mechanism that ensures that standard gravity is recovered near astrophysical bodies. In a recently introduced class of…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Ryo Saito , Daisuke Yamauchi , Shuntaro Mizuno , Jérôme Gleyzes , David Langlois

We study the clustering Generalized Chaplygin Gas (GCG) as a possible candidate for dark matter-dark energy unification. The vanishing speed of sound ($c_{s}^2 = 0$) for the GCG fluid can be obtained by incorporating higher derivative…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 Sumit Kumar , Anjan A. Sen

We consider perturbative modifications of the Friedmann equations in terms of energy density corresponding to modified theories of gravity proposed as an alternative route to comply with the observed accelerated expansion of the universe.…

General Relativity and Quantum Cosmology · Physics 2015-05-13 L. Fernández-Jambrina , R. Lazkoz

In this work we investigate the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by Loop quantum cosmology. Dark energy in the form of Generalised Cosmic Chaplygin gas is…

General Physics · Physics 2015-06-04 Ratul Chowdhury , Prabir Rudra

A relatively simple approach to noncommutative gravity utilizes the gauge theory formulation of general relativity and involves replacing the Lorentz gauge group by a larger group. This results in additional field degrees of freedom which…

High Energy Physics - Theory · Physics 2009-07-30 A. Stern

The cosmological observations suggest that the presently accelerating universe should be filled by an exotic form of matter, violating the strong energy condition, of unknown nature and origin. We propose the viscous dark matter of a source…

General Relativity and Quantum Cosmology · Physics 2020-08-05 Marek Szydlowski , Adam Krawiec

In this letter, I have proposed a model of variable modified Chaplygin gas and shown its role in accelerating phase of the universe. I have shown that the equation of state of this model is valid from the radiation era to quiessence model.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ujjal Debnath

In this paper, the model of interaction is studied between $f(T,\mathcal{T})$ gravity and modified Chaplygin gas in FRW-flat metric. We obtain the Friedmann equations in the framework of teleparallel gravity by vierbein field. We consider…

General Relativity and Quantum Cosmology · Physics 2017-05-19 T. Mirzaei Rezaei , Alireza Amani