Density of the universe

In article ,
"OG" wrote:

snip

If the suggestion is that clusters of galaxies are found as 'sheets' rather
than 'volumes', does this mean that the mass enclosed in a sphere of radius
r increases with an exponent less than 3? , r^2.5 perhaps?

Do we have an 'accepted value' for the exponent over sufficiently large
scales?

A quick search turned up this abstract at http://tinyurl.com/2r79s2
that looks relevant: Montuori, Labini, & Amici, "Statistical properties
of galaxy cluster distribution", 1997.

"We analyze subsamples of Abell and ACO cluster catalogs, in order to
study the spatial properties of the large-scale matter distribution.
[...] The cluster samples show fractal correlations up to sample limits
(‰70h^-1 Mpc) with fractal dimension D ‰ 2, without any tendency towards
homogenization. Our analysis shows that the standard correlation methods
are incorrect [...] Moreover we conclude that galaxies and clusters are
two different representations of the same self-similar structure and
that the correlations of clusters are the continuation of those of
galaxies to larger scales."

And this New Scientist article from a few years back:

http://space.newscientist.com/articl...tured-universe.
html

"From their measurements, Pietronero and his colleagues estimate that D
is about 2.1, implying that the Universe is fractal on scales up to 300
million light years. There is a proviso, however. "We should not forget
the invisible 'dark' matter, which is thought to account for at least 90
per cent of the mass in the Universe," says Sylos Labini."

--
Odysseus