Cosmological constraints on the DGP braneworld model with gamma-ray bursts

We investigate observational constraints on the Dvali, Gabadadze and Porrati (DGP) model with Gamma-ray bursts (GRBs) at high redshift obtained directly from the Union2 Type Ia supernovae data set. With cosmology-independent GRBs, the Union2 set, as well as the cosmic microwave background observation from the WMAP7 result, the baryon acoustic oscillation, the baryon mass fraction in clusters and the observed H(z) data, we obtain that the best-fit values of the DGP model are {Omega(M0), Omega r(c)} = {0.235(-0.014)(+0.015), 0.138(-0.048)(+0.051)}, which favor a flat universe, and the transition redshift of the DGP model is z(T) = 0.67(-0.04)(+0.03). These results lead to more stringent constraints than the previous results for the DGP model.