Another confirmation of the existence of dark energy.

Boud Roukema boud w
Pon, 25 Mar 2002, 12:09:13 CET

Cze¶æ wszysce,

> ---------------------------------------------------
> A team of UK and Australian astronomers has discovered new, independent
> evidence that the expansion of the universe is accelerating. Their findings
> have just appeared in the Monthly Notices of the Royal Astronomical Society.
> A team of 27 astronomers led by Professor George Efstathiou of
> the University of Cambridge has published strong evidence for the
> existence of dark energy using an entirely different technique.
> Their results show that the universe is full of dark energy, completely
> consistent with the earlier supernovae results. "Dark energy appears to
> exist and to dominate over more conventional types of matter" says
> Professor Efstathiou. "An explanation of the dark energy may involve
> String Theory, extra dimensions or even what happened before the Big Bang.
> At present nobody knows. The ball is now firmly in the theorists court."

You're right Andrzej, the 2dF galaxy z survey people invest pretty
heavily in propaganda about rather modest results! But they need to
justify their funding under the Rupert Murdoch/IMF/WTO/WB
media/political regime which opposes rational discussion and
balanced publication of empirical data... So we can't really blame
them for struggling for survival!  And nothing seems to be incorrect
in the RAS news release, it is just misleading by omission - which
is a perfectly standard method of propaganda in democracies.
(See or  for media
criticism from the heart of what's left of Her Majesty's Empire.)

Anyways, here's the article:
"Evidence for a non-zero Lambda and a low matter density from a
combined analysis of the 2dF Galaxy Redshift Survey and Cosmic
Microwave Background Anisotropies"

They don't even bother to cite the paper based on the 2dF *quasar* z
survey, posted three months earlier:

which has evidence for a non-zero Lambda and a low matter density from
analysis of a *single* survey, the 2QZ-10K early release.

Gary Mamon thinks we should spend some time in making propaganda,
sorry, "media relations", for our result, but I think it's better to
concentrate on getting new results which cannot be ignored. ;)
And then the best way for a propaganda campaign, sorry, for public
relations, will be to release a GNU/Linux self-contained easy-to-compile
and run software package which any cosmologist can easily run for
herself and be convinced of the results...

BTW, Efstathiou et al. use maximum likelihood, which means, if I
understand it correctly, that they really only show that a non-zero
Lambda, low Omega_m model is *more* likely than other models, they
don't reject a zero-Lambda model.

In contrast, we use absolute probabilities of null hypothesis rejection,
so we *do* reject the zero-Lambda model and high matter density models.



Więcej informacji o liście Cosmo-torun