Branes: cosmological surprise and observational deception
Résumé
Using some supernovae and CMB data, we constrain the Cardassian, Randall-Sundrum, and Dvali-Gabadadze-Porrati brane-inspired cosmological models. We show that a transient acceleration and an early loitering period are usually excluded by the data. Moreover, the three models are equivalent to some usual quintessence/ghost dark energy models defined by a barotropic index gamma_phi depending on the redshift. We calculate this index for each model and show that they mimic a universe close to a Lambda CDM model today.