witam,
So Burbidge/Hoyle/Narlikar "Reloaded" have got some media coverage. Fine.
"Omega_matter = 1 (was Re: gas question)" http://www.astro.uni.torun.pl/sympa/shape-univ/2003-11/msg00005.html
The article by Blanchard et al: http://arxiv.org/abs/astro-ph/0311381
Look carefully at the figures. The triple-dotted-dashed line is the model for an (Om_m=0.3, Om_Lambda=0.7). It's hard to find, but once you find it, you'll see it matches the observations very, very nicely.
According to the authors, this triple-dotted-dashed line is for eq.~(6), which replaces eq.~(2). The difference between the dtwo eqns is a factor of (1+z).
The authors' derivation of eq.~(2), in other papers, obtains this (1+z) factor from the density of the Universe at the time that the cluster virialises. So unless you throw out rho = rho_0 (1+z)^3 , it's hard to change the derivation.
However, if you just look at another derivation of the equivalent of eq.~(2), i.e. a T-M relation, and look at the z evolution of, e.g. equation (73) of
Niayesh Afshordi, Renyue Cen http://arxiv.org/abs/astro-ph/0105020
then the (1+z) factor becomes essentially (1+ not much) over the relevant redshift range.
In other words, Blanchard et al's figures, with Afshordi & Cen's version of the T-M relation, give the concordance model.
Again in simpler words, Blanchard et al think that clusters form in one way, Afshordi & Cen think they form in a somewhat different way, leading to moderately different T-M relations and hence totally different local curvature parameter inferences.
It's good to have dissidents around :). Sometimes they're right, sometimes they're wrong.
pozd boud
On Tue, 16 Dec 2003, Andrzej Marecki wrote:
NEWSALERT: Saturday, December 13, 2003 @ 2327 GMT
The latest news from Astronomy Now and Spaceflight NowHAS XMM-NEWTON CAST DOUBT OVER DARK ENERGY?
In a survey of distant clusters of galaxies, European Space Agency's XMM-Newton observatory has found puzzling differences between today's clusters of galaxies and those present in the Universe around seven thousand million years ago.
Alain Blanchard of the Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrenees and his team use the results to calculate how the abundance of galaxy clusters changes with time. Blanchard, knowing that this conclusion will be highly controversial, said: "To account for these results you have to have a lot of matter in the Universe and that leaves little room for dark energy."
http://spaceflightnow.com/news/n0312/12darkenergy/
[...]
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-- Andrzej