Observational constraints on non-minimally coupled Galileon model

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 the 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(m0) = 0.263(-0.031)(+0.031), n = 1.53(-0.37)(+0.21) (at the 95 % confidence level) with chi(2)(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.