Constraining Dvali-Gabadadze-Porrati gravity from observational data

The accelerating expansion of our Universe at present could be driven by an unknown energy component (dark energy) or a modification of general relativity (modified gravity). In this paper we revisit the constraints on a phenomenological model which interpolates between the pure ΛCDM model and the Dvali-Gabadadze-Porrati braneworld model with an additional parameter α. Combining the cosmic microwave background , baryon acoustic oscillations, and type Ia supernovae, as well as some high-redshift observations, such as the gamma-ray bursts and the measurements of linear growth factors, we obtain the tight constraint on the parameter α=0.254±0.153 (68% C.L.), which implies that the flat Dvali-Gabadadze-Porrati model is incompatible with the current observations, while the pure ΛCDM model still fits the data very well. Finally, we simulate the future measurements with higher precisions and find that the constraint on α can be improved by a factor of 2 when compared to the present constraints.