Supernova limits on brane world cosmology

By combining the first year data from the Supernova Legacy Survey (SNLS) and the recent detection of the baryon acoustic peak in the Sloan Digital Sky Survey data, we are able to place strong constraints on models where the cosmic acceleration is due to the leakage of gravity from the brane into the bulk on large scales. In particular, assuming that one can neglect differences in structure formation on small scales between DGP and ΛCDM, we show that the DGP model in a spatially flat universe is incompatible with the observations. We generalize our analysis to phenomenological toy models where the curvature of the brane enters into the Friedmann equations in different ways.