Cosmological constraints for an Eddington-Born-Infeld field

We consider the Eddington-Born-Infeld (EBI) model here without assuming any cosmological constant. The EBI scalar field is supposed to play a role of both dark matter and dark energy. Different eras in cosmology are reconstructed for the model. A comparison is drawn with $\Lambda$CDM model using Supernova Ia, WMAP7 and BAO data. It seems that the EBI field in this form does not give good fit to observational data in comparison to the $\Lambda$CDM model.
Comment: 8 pages, 4 figures