Is the Fate of the Universe Truly Determined by Dark Energy?

[skydivephil]

The BBc just publsihed this story:
http://www.bbc.co.uk/news/science-environment-11030889

The conclusion is:
"Professor Priyamvada Natarajan of Yale University, a leading cosmologist and co-author of this study, said that the findings finally proved "exactly what the fate of the Universe will be". "

Surely this is premature? Until we udnerstand what dark energy is we can't say its a contsant and if its not constant it may die down or even reverse and so the ultimate fate of the unvierse is still unknown.

 

[George Jones]

Constant dark energy/cosmology constant has equation of state [itex]p = -\rho[itex], i.e., $w = -1$. While it cannot be ruled out that w will remain constant, this paper's result is consistent (with smaller error bands than before) with constant $w = -1$.

From the Science article's abstract:

Combining our cosmological constraints with those from x-ray clusters and the Wilkinson Microwave Anisotropy Probe 5-year data gives Wm = 0.25 T0.05 and w = −0.97 +- 0.07

From the end of the article:

Our results—when combined with the results from WMAP5 (40), the supernovae “Gold sample” (4), the Supernovae Legacy Survey (SNLS) (41), the ESSENCE Supernova Survey (SNEssence) (42), and the BAO peak from the Sloan Digital Sky Survey (SDSS) (16)—give 0.23 < $\Omega_m$ < 0.33 and −1.12 < w < −0.82 at the 99% confidence level.