Mubasher Jamil, Davood Momeni, Ratbay Myrzakulov
As an extension of Dvali-Gabadadze-Porrati (DGP) model, the Galileon theory has been proposed to explain the "self-accelerating problem" and "ghost instability problem". In this Paper, we extend the Galileon theory by considering a non-minimally coupled Galileon scalar with gravity. We find that crossing of phantom divide line is possible for such model. Moreover we perform the statefinder analysis and $Om(z)$ diagnostic and constraint the model parameters from the latest Union 2 type Ia Supernova (SNe Ia) set and the baryonic acoustic oscillation (BAO). Using these data sets, we obtain the constraints $\Omega_\text{m0}=0.263_{-0.031}^{+0.031}$, $n=1.53_{-0.37}^{+0.21}$ (at the 95% confidence level) with $\chi^2_{\text{min}}=473.376$. Further we study the evolution of the equation of state parameter for the effective dark energy and observe that SNe Ia + BAO prefers a phantom-like dark energy.
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http://arxiv.org/abs/1302.0129
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