Dimensionless coordinate distances to supernovae

In an earlier paper (Daly & Djorgovski, 2003ApJ...597....9D) we proposed a novel method to determine the expansion rate E(z) and the deceleration parameter q(z) in a largely model-independent way, directly from the data on coordinate distances y(z). Here we expand this methodology to include measurements of the pressure of dark energy p(z), its normalized energy density fraction f(z), and the equation-of-state parameter w(z).

We then apply this methodology to a new, combined data set of distances to supernovae and radio galaxies.