Constraining Dvali-Gabadadze-Porrati gravity from observational data

Abstract

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 {lambda}CDM model and the Dvali-Gabadadze-Porrati braneworld model with an additional parameter {alpha}. 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 {alpha}=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 {lambda}CDM model still fits the data very well. Finally, we simulate the future measurements with higher precisions and find that the constraint on {alpha} can be improved by a factor of 2 when compared to the present constraints.