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相关论文: Comment on Ricci dark energy in Chern-Simons modif…

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The Modified Chaplygin Gas (MCG) model belongs to the class of a unified models of dark energy (DE) and dark matter (DM). It is characterized by an equation of state (EoS) $p_c = B\rho - A/\rho^{\alpha}$, where the case $B=0$ corresponds to…

宇宙学与河外天体物理 · 物理学 2011-01-27 J. C. Fabris , C. Ogouyandjou , J. Tossa , H. E. S. Velten

We investigate the background dynamics when dark energy is coupled to dark matter in the universe described by loop quantum cosmology. We consider dark energy of the form modified Chaplygin gas. The dynamical system of equations is solved…

综合物理 · 物理学 2011-04-04 Mubasher Jamil , Ujjal Debnath

We have explored the possibility of the co-existence of two forms of dark energy in the form of an alternative Generalized Chaplygin Gas (GCG) along with a scalar field of field theoretic or extra dimensional origin in the background of a…

广义相对论与量子宇宙学 · 物理学 2026-01-28 Mahasweta Biswas , Rikpratik Sengupta , Ujjal Debnath

A new model for the universe filled with a generalized Chaplygin fluid is considered which unitarily describes as a single vacuum entity both a quintessence scalar field and a cosmological constant, so unifying the notion of dark energy.…

天体物理学 · 物理学 2008-11-26 Pedro F. Gonzalez-Diaz

We propose a new fluid model of dark energy for $-1 \leq \omega_{\text{eff}} \leq 0$ as an alternative to the generalized Chaplygin gas models. The energy density of dark energy fluid is severely suppressed during barotropic matter dominant…

宇宙学与河外天体物理 · 物理学 2010-11-23 Hoavo Hova , Huanxiong Yang

We verify the consistency of the G\"odel-type solutions within the four-dimensional Chern-Simons modified gravity with the non-dynamical Chern-Simons coefficient, for different forms of matter including dust, fluid, scalar field and…

高能物理 - 理论 · 物理学 2016-08-23 P. J. Porfirio , J. B. Fonseca-Neto , J. R. Nascimento , A. Yu. Petrov , J. Ricardo , A. F. Santos

Evolution of the universe with modified holographic Ricci dark energy model is considered. Dependency of the equation of state parameter and deceleration parameter on the redshift and model parameters are obtained. It is shown that the…

宇宙学与河外天体物理 · 物理学 2019-05-13 Titus K Mathew , Jishnu Suresh , Divya Divakaran

Within our recent thermodynamic model of gravity the dark energy is identified with the energy of collective gravitational interactions of all particles in the universe, which is missing in the standard treatments. For a simple model…

综合物理 · 物理学 2014-04-24 Merab Gogberashvili , Igor Kanatchikov

In this work the modified Chaplygin gas is related to a cosmological scalar field. Analytical results, more general than the solutions previously shown in the literature, are presented for the case when the curvature is absent, and one…

广义相对论与量子宇宙学 · 物理学 2008-03-03 Sandro Silva e Costa

We discuss the modified gravity which includes negative and positive powers of the curvature and which provides the gravitational dark energy. It is shown that in GR plus the term containing negative power of the curvature the cosmic…

高能物理 - 理论 · 物理学 2009-09-17 M. C. B. Abdalla , Shin'ichi Nojiri , Sergei D. Odintsov

For higher-derivative f(R) gravity where R is the Ricci scalar, a class of models is proposed which produce viable cosmology different from the LambdaCDM one at recent times and satisfy cosmological, Solar system and laboratory tests. These…

天体物理学 · 物理学 2009-07-09 Alexei A. Starobinsky

In this paper we investigate the cosmological effects of modified gravity with string curvature corrections added to Einstein-Hilbert action in the presence of a dynamically evolving scalar field coupled to Riemann invariants. The scenario…

高能物理 - 理论 · 物理学 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov , M. Sami

It is well known that string theories naturally compactify on anti-de Sitter spaces, and yet cosmological observations show no evidence of a negative cosmological constant in the early Universe's evolution. In this letter we present two…

宇宙学与河外天体物理 · 物理学 2011-05-03 Tomislav Prokopec

We investigate the correspondence between the ghost and Chaplygin scalar field dark energy models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe containing the interacting dark energy with dark matter.…

综合物理 · 物理学 2013-02-28 F. Adabi , K. Karami , M. Mousivand

We discuss a no-go theorem for the novel Ricci-inverse theory of modified gravity. By considering a static spherically symmetric matter distribution embedded within a de Sitter cosmology, we demonstrate that achieving a stable Sub-Horizon…

宇宙学与河外天体物理 · 物理学 2025-01-22 Mattia Scomparin

Chern-Simons modified gravity is an effective extension of general relativity that captures leading-order, gravitational parity violation. Such an effective theory is motivated by anomaly cancelation in particle physics and string theory.…

高能物理 - 理论 · 物理学 2015-05-13 Stephon Alexander , Nicolas Yunes

Dark energy cosmology is considered in a modified Gauss-Bonnet model of gravity with and without a scalar field. It is shown that these generalizations of General Relativity endow it with a very rich cosmological structure: it may naturally…

广义相对论与量子宇宙学 · 物理学 2015-05-18 Emilio Elizalde , Ratbay Myrzakulov , Valery V. Obukhov , Diego Sáez-Gómez

A formalism for the appearance of dark energy in the matter dominated era, leading to a persistent de Sitter expansion at the late time is proposed. Our framework is a hybrid quintessence model with a non-minimal coupling to the Ricci…

广义相对论与量子宇宙学 · 物理学 2018-11-29 H. Mohseni Sadjadi

A combination of recent observational results has given rise to what is currently known as the dark energy problem. Although several possible candidates have been extensively discussed in the literature to date the nature of this dark…

天体物理学 · 物理学 2009-11-07 Abha Dev , J. S. Alcaniz , Deepak Jain

In this paper, we reexamine the generalized Chaplygin gas (GCG) cosmology with the sign-changeable interaction. The dynamical analysis show that there exists de-Sitter attractors in this model, which means that the late-time behaviors of…

广义相对论与量子宇宙学 · 物理学 2015-10-13 Ping Xi , Ping Li