Paper detail

Tracking and coupled dark energy as seen by WMAP

The satellite experiment WMAP has produced for the first time a high-coverage, high resolution survey of the microwave sky, releasing publicly available data that are likely to remain unrivalled for years to come. Here we compare the WMAP temperature power spectrum, along with an exhautive compilation of previous experiments, to models of dark energy that allow for a tracking epoch at the present, deriving updated bounds on the dark energy equation of state and the other cosmological parameters. Moreover, we complement the analysis by including a coupling of the dark energy to dark matter. The main results are: a) the WMAP data alone constrains the equation of state of tracking dark energy to be w_ϕ<-0.67(-0.49) to 68%(95%) (confining the analysis to w_ϕ>-1), which implies for an inverse power law potential an exponent α<0.99(2.08); b) the dimensionless coupling to dark matter is |β|<0.07(0.13). Including the results from the supernovae Ia further constrains the dark energy equation of state.