Another coincidence problem for ?
Abstract
Over the last nine years of cosmic microwave background observations, the Wilkinson Microwave Anisotropy Probe (WMAP) results were consistent with a cosmological model in which the age of the Universe is one Hubble time, and the time-averaged value of the deceleration parameter is consistent with zero. This curious observation has been put forward as a new coincidence problem for the concordance cosmology, which is in fact a `greater' coincidence than the near equality of the density parameters of matter and the cosmological constant. At the moment of writing these conference proceedings, the Planck Collaboration has released its first cosmological data, which revealed a small shift in the cosmological parameters when compared to WMAP. We show that under the assumption of a spatially flat cosmology, Planck's results remove this coincidence problem for at greater than 99\% confidence level.