Rejoinder to "No Evidence of Dark Energy Metamorphosis", astro-ph/0404468

Abstract

In a recent paper (astro-ph/0311364) Alam et al argued that the SNe data of Tonry et al 2003 and Barris et al 2003 appear to favour DE which evolves in time, provided no other priors are invoked. (The effect of invoking priors such as the age of the Universe, the values of $H_0$ and $Ω_m$ and CMB/LSS observations could modify this conclusion, as demonstrated in astro-ph/0403687 and other recent papers.) The approach adopted by Alam et al to reconstruct the properties of DE was severely (and, as we shall show below -- unfairly) criticized by Jönsson et al in astro-ph/0404468. In this paper we re-examine the parametrisation used in astro-ph/0311364 and show that, contrary to the claims of Jönsson et al, the results obtained from this reconstruction are robust and therefore representative of the true nature of dark energy.