6 papers
Constraining the Anisotropic Expansion of Universe
Rong-Gen Cai, Yin-Zhe Ma, Bo Tang +1
We study the possibly existing anisotropy in the accelerating expansion universe with the Union2 Type Ia supernovae data and Gamma-ray burst data. We construct a direction-dependen…
More on QCD Ghost Dark Energy
Rong-Gen Cai, Zhong-Liang Tuo, Ya-Bo Wu +1
The difference between vacuum energy of quantum fields in Minkowski space and in Friedmann-Robterson-Walker universe might be related to the observed dark energy. The vacuum energy…
Figure of Merit and Different Combinations of Observational Data Sets
Qiping Su, Zhong-Liang Tuo, Rong-Gen Cai
To constrain cosmological parameters, one often makes a joint analysis with different combinations of observational data sets. In this paper we take the figure of merit (FoM) for D…
Direction Dependence of the Deceleration Parameter
Ronggen Cai, Zhongliang Tuo
In this paper we study the possibly existing anisotropy in the acceleration expansion by use of the full sample of Union2 data. Using the hemisphere comparison method to search for…
Detecting the cosmic acceleration with current data
Ronggen Cai, Zhongliang Tuo
The deceleration parameter q as the diagnostic of the cosmological accelerating expansion is investigated. By expanding the luminosity distance to the fourth order of redshift and…
Notes on Ghost Dark Energy
Rong-Gen Cai, Qiping Su, Zhong-Liang Tuo +1
We study a phenomenological dark energy model which is rooted in the Veneziano ghost of QCD. In this dark energy model, the energy density of dark energy is proportional to Hubble…