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Related papers: Ricci dark energy in Chern-Simons modified gravity

200 papers

Quantum treatment of physical reference frame leads to the Ricci flow of quantum spacetime, which is a quite rigid framework to quantum and renormalization effect of gravity. The theory has a low characteristic energy scale described by a…

General Relativity and Quantum Cosmology · Physics 2023-04-27 M. J. Luo

We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantom-like dark energy is excluded.…

Astrophysics · Physics 2009-10-29 M. C. Bento , O. Bertolami , A. A. Sen

We study the correspondence between field theoretic and holographic dark energy density of the universe with the modified Chaplygin gas (MCG) respectively both in a flat and non-flat FRW universe. We present an equivalent representation of…

High Energy Physics - Theory · Physics 2008-09-23 B. C. Paul , P. Thakur , A. Saha

In this paper, we consider three different models of dark energy in higher dimensional space-time and discuss about some cosmological parameters numerically. The first model is a single component universe including viscous varying modified…

General Relativity and Quantum Cosmology · Physics 2014-06-13 M. Khurshudyan , J. Sadeghi , M. Hakobyan , H. Farahani , R. Myrzakulov

This paper considers the spherically symmetric gravitational collapse in the background of Chaplygin gas as dark energy component. The dark energy is assumed to be generalized and modified Chaplygin gas. The exterior of the star is…

General Relativity and Quantum Cosmology · Physics 2023-03-14 Anjali Pandey , Rajesh Kumar , Sudhir Kumar Srivastava

We consider new models of dark energy with finite time future singularities, by introducing the pressure density as a function of the scale factor. This approach gives acceptable phenomenological models of dark energy, practically…

General Relativity and Quantum Cosmology · Physics 2019-07-17 L. N. Granda

In the current framework of Einstein's equations in general relativity (GR), gravity is described by the spacetime curvature. However, there are other descriptions where the origin of gravity can be understood through torsion and…

General Relativity and Quantum Cosmology · Physics 2022-12-02 Nakul Aggarwal , Ali Pourmand , Fatimah Shojai , Harish Parthasarathy

We present a holographic dark energy model of the universe considering modified generalized Chaplygin gas (GCG). The modified GCG behaves as an ordinary barotropic fluid in the early epoch when the universe was tiny but behaves subsequently…

General Relativity and Quantum Cosmology · Physics 2007-11-21 B. C. Paul , P. Thakur , A. Saha

The present work reports study on the interacting Ricci dark energy in a modified gravity theory named $f(R,T)$ gravity. The specific model $f(R,T)=\mu R+\nu T$ (proposed by R. Myrzakulov, arXiv:1205.5266v2) is considered here. For this…

General Physics · Physics 2014-03-31 Surajit Chattopadhyay

The modified F(R)-scalar-Gauss-Bonnet gravity is proposed as dark energy model. The reconstruction program for such theory is developed. It is explicitly demonstrated that the known classical universe expansion history (deceleration epoch,…

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

We review the essential features of the Chaplygin gas cosmological models and provide some examples of appearance of the Chaplygin gas equation of state in modern physics. A possible theoretical basis for the Chaplygin gas in cosmology is…

General Relativity and Quantum Cosmology · Physics 2016-11-09 V. Gorini , A. Kamenshchik , U. Moschella , V. Pasquier

We highlight a viable mechanism leading to the formation of dark energy structures on sub-horizon cosmological scales, starting from linear perturbations in scalar-tensor cosmologies. We show that the coupling of the dark energy scalar…

Astrophysics · Physics 2009-11-07 Francesca Perrotta , Carlo Baccigalupi

In this paper, we study R\'{e}nyi holographic dark energy model in the context of Chern Simons (CS) modified gravity theory. Different cosmological parameters such as energy density, deceleration parameter, equation of state, square of…

General Relativity and Quantum Cosmology · Physics 2021-10-04 Sarfraz Ali , Sarfaraz Khan , Sadia Sattar , Amare Abebe

Taking up four model universes we study the behaviour and contribution of dark energy to the accelerated expansion of the universe, in the modified scale covariant theory of gravitation. Here, it is seen that though this modified theory may…

General Relativity and Quantum Cosmology · Physics 2020-01-28 Koijam Manihar Singh , Sanjay Mandal , Longjam Parbati Devi , P. K. Sahoo

We review the evidence for recently accelerating cosmological expansion or "dark energy", either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any Dark Energy constituent. If…

Astrophysics · Physics 2007-05-23 Sidney Bludman

The modified gravity with $f(R)=R^{1+\epsilon}$ ($\epsilon>0$) allows a scaling solution where the density of gravity sector follows the density of the dominant fluid. We present initial conditions of background and perturbation variables…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Chan-Gyung Park , Jai-chan Hwang , Hyerim Noh

We analyse the role, on large cosmological scales and laboratory experiments, of the leading curvature squared contributions to the low energy effective action of gravity. We argue for a natural relationship $c_0\lambda^2\simeq 1$ at…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Philippe Brax , Patrick Valageas , Pierre Vanhove

In this paper, we attempt to explore the possibility of a obtaining a viable emergent universe scenario supported by a type of fluid known as the extended Chaplygin gas, which extends a modification to the equation of state of the well…

General Relativity and Quantum Cosmology · Physics 2025-08-13 Rikpratik Sengupta , Anirban Chanda , B C Paul , M Kalam

$F(R)$ models for dark energy generally exhibit a weak curvature singularity, which can be cured by adding an $R^2$ term. This correction allows for a unified description of primordial and late-time accelerated expansions. However, most…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-04 Hua Chen

We review some modified gravity models which describe the gravitational dark energy and the possibility of cosmic speed-up. The new consistent version of such theory which contains inverse and HD curvature terms as well as new type of…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov