Observational constraints on modified gravity models and the Poincare dodecahedral topology

We study observational constraints on models that account for the accelerated expansion of the universe via infrared modifications to general relativity, namely, the Dvali-Gabadadze-Porrati braneworld model as well as the Dvali-Turner and Cardassian models. We find that significant constraints can be placed on the parameters of each model using type Ia supernovae data together with the baryon acoustic peak in the large-scale correlation function of the Sloan Digital Sky Survey of luminous red galaxies and the Cosmic Microwave Background Radiation shift parameter data. Moreover, by considering the Poincare dodecahedral space as the circles-in-the-sky observable spatial topology, we show that the detection of a such a nontrivial topology would provide relevant additional constraints, particularly on the curvature parameter, for all models.