Dark energy constraints from joint analysis of standard rulers and standard candles

Abstract

We performed joint analysis of five cosmological models invoked to explain the accelerating expansion of the Universe. We used the data from strong gravitational lensing systems, locations of cosmic microwave background acoustic peaks and baryon acoustic oscillation data in combination with supernova Ia data (Union2 compilation). The observables we used came from both standard rulers and standard candles, so they had different parameter degeneracies and different restrictive powers in the parameter spaces of cosmological models. The best fits we obtained for the model parameters in joint analysis turned out to prefer cases effectively equivalent to the ΛCDM model. They were also in agreement with other combined studies performed by other authors on different sets of diagnostic probes. Information theoretic methods used to assess which model is most supported by the data lead to the conclusion that the concordance model ΛCDM is clearly preferred in joint analysis. The quintessence (both having constant or time varying equation of state) and Chaplygin gas get considerably less support from the data while the brane world (DGP) scenario is practically ruled out.