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We study the statefinder parameters in the Yang-Mills condensate dark energy models, and find that the evolving trajectories of these models are different from those of other dark energy models. We also define two eigenfunctions of the…

General Relativity and Quantum Cosmology · Physics 2009-04-10 Wen Zhao

In seeking a model solving the coincidence problem, the effective Yang-Mills condensate (YMC) is an alternative candidate for dark energy. A study is made for the model up to the 2-loop order of quantum corrections. It is found that, like…

Astrophysics · Physics 2008-11-26 T. Y. Xia , Y. Zhang

The coincidence problem is studied for the dark energy model of effective Yang-Mills condensate in a flat expanding universe during the matter-dominated stage. The YMC energy $\rho_y(t)$ is taken to represent the dark energy, which is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Y. Zhang , T. Y. Xia , W. Zhao

We review the quantum Yang-Mills condensate (YMC) dark energy models. As the effective Yang-Mills Lagrangian is completely determined by the quantum field theory, there is no adjustable parameter in the model except the energy scale. In…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-04 W. Zhao , Y. Zhang , M. L. Tong

This work is a comprehensive investigation of the Yang-Mills condensate (YMC) dark energy (DE) model, which is extended to include the 3-loop quantum corrections. We study its cosmic evolution and the possibility of crossing phantom divide…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Shuang Wang , Yang Zhang , Tian-Yang Xia

Models based on Yang-Mills condensate (YMC) have been advocated in the literature and claimed to be successful candidates to explain dark energy. Several instantiations of this simple idea have been considered, the most promising of which…

General Relativity and Quantum Cosmology · Physics 2016-03-02 Pietro Donà , Antonino Marcianò , Yang Zhang , Claudia Antolini

The coincidence problem is studied in the effective Yang-Mills condensate dark energy model. As the effective YM Lagrangian is completely determined by quantum field theory, there is no adjustable parameter in this model except the energy…

Astrophysics · Physics 2010-11-11 Wen Zhao , Yang Zhang

Motivated by Yang-Mills dark energy model, we propose a new model by introducing a logarithmic correction. we find that this model can avoid the coincidence problem naturally and gives an equation of state $w$ smoothly crossing -1 if an…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Ming-Lei Tong , Yang Zhang , Zheng-Wen Fu

We introduce a new cosmological diagnostic pair $\lbrace r,s\rbrace$ called Statefinder. The Statefinder is dimensionless and, like the Hubble and deceleration parameters $H(z)$ and $q(z)$, is constructed from the scale factor of the…

Astrophysics · Physics 2011-07-19 Varun Sahni , Tarun Deep Saini , A. A. Starobinsky , Ujjaini Alam

The evolution of the electric and magnetic components in an effective Yang-Mills condensate dark energy model is investigated. If the electric field is dominant, the magnetic component disappears with the expansion of the Universe. The…

General Relativity and Quantum Cosmology · Physics 2009-04-10 Wen Zhao , Donghui Xu

In this paper, we study the possibility of building Yang-Mills(YM) field dark energy models with equation of state (EoS) crossing -1, and find that it can not be realized by the single YM field models, no matter what kind of lagrangian or…

Astrophysics · Physics 2009-11-13 Wen Zhao , Yang Zhang

Using the recently released Union2 compilation with 557 Type Ia supernovae, the shift parameter of cosmic microwave background given by the WMAP7 observations, and the baryon acoustic oscillation measurement from the Sloan Digital Sky…

General Relativity and Quantum Cosmology · Physics 2011-10-26 Z. W. Fu , Y. Zhang , M. L. Tong

In the present work, we perform a comparative study of different interacting dark energy (DE) models using the Statefinder diagnostics. In particular, 17 different forms of the energy transfer rate $Q$ between DE and dark matter (DM) were…

General Relativity and Quantum Cosmology · Physics 2023-10-09 Raul Carrasco , Angel Rincon , Joel Saavedra , Nelson Videla

As an extension of $\Lambda$CDM, the decaying vacuum model (DV) describes the dark energy as a varying vacuum whose energy density decays linearly with the Hubble parameter in the late-times, $\rho_\Lambda(t) \propto H(t)$, and produces the…

General Relativity and Quantum Cosmology · Physics 2009-09-02 Ming-Lei Tong , Yang Zhang

We argue that the recently introduced "statefinder parameters" (Sahni et al., JETP Lett. 77, 201 (2003)), that include the third derivative of the cosmic scale factor, are useful tools to characterize interacting quitessence models. We…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Winfried Zimdahl , Diego Pavon

We investigate the attractor solution in the coupled Yang-Mills field dark energy models with the general interaction term, and obtain the constraint equations for the interaction if the attractor solution exists. The research also shows…

General Relativity and Quantum Cosmology · Physics 2009-09-28 Wen Zhao

Observations of high redshift supernovae indicate that the universe is accelerating. The hypothesis of `Dark energy' (cosmological constant, scalar field tracker potentials, braneworld models, etc.) has been advanced to explain this…

Astrophysics · Physics 2007-05-23 Varun Sahni

The problem of the cosmic coincidence is a longstanding puzzle. This conundrum may be solved by introducing a coupling between the two dark sectors. In this Letter, we study two cases of the coupled quintessence scenario. $(a)$ Assume that…

Astrophysics · Physics 2009-11-10 Xin Zhang

We review basic features of cosmological models with large-scale classical non-Abelian Yang-Mills (YM) condensates. There exists a unique SU(2) YM configuration (generalizable to larger gauge groups) compatible with homogeneity and isotropy…

General Relativity and Quantum Cosmology · Physics 2009-01-21 Dmitri V. Gal'tsov

In this paper we study the statefinder parameters for the tachyon dark energy model. There are two kinds of stable attractor solutions in this model. The statefinder diagrams characterize the properties of the tachyon dark energy model. Our…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ying Shao , Yuanxing Gui
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