Dark Energy is dead. Long live GR.

Recent GR recalculation, taking into account the non-isotropic
distribution of matter in the universe, appears to remove the need for
dark stuff (matter/energy) in explaining the (apparent) acceleration
of expansion of the universe.

Here are some links:

http://arxiv.org/abs/astro-ph/0510059

http://xxx.lanl.gov/abs/astro-ph/0310342

http://www.iop.org/EJ/article/1367-2...p7_10_377.html

Occams razor suggests that this is a far more palatable resolution
than dark stuff.

Here is a quote from discussion on Slashdot, which I reproduce without
permission:

"I am, for the record, a physicist.

Here's the slightly more condensed version of this story. Einstein's
theory of General Relativity (GR), which incidentally should the Law
of GR by today's standards, gives a large set of differential
equations to be solved. When this was first being applied to Cosmology
in the 1920's, some basic assumptions about the universe had to made
in order to solve the GR equations: it is isotropic (same in all
directions), and homogeneous (uniform everywhere). They were primarily
made for two reasons: mathematical expediency (this is the simplest
sort of non-trivial universe you can have), and this didn't conflict
with any observations at the time. Solving the GR equations with these
assumptions gives fairly simple equations for the time evolution of
the universe, leading to the standard model of Cosmology (called the
Lambda-CDM model).

As you would imagine, we have vastly more astronomical data now then
we did in the 20's. To explain what we observe now, particularly the
cosmic microwave background data, with these evolution equations we
need to include a constant expansion term. This expansion would have
to be from something uniformly distributed throughout the universe
with negative pressure (very reminiscent of phlogiston, isn't it?)
which we call "Dark Energy". So, based on current data and using the
standard model to explain certain properties of the universe, it must
consist of around 73% dark energy. Considering that this is the bulk
of the universe and that, other than negative pressure, we have no
idea what dark energy is or what it's properties are, this leads to a
scientifically troubling state of affairs.

However, modern sky surveys show that the universe is neither
isotropic nor homogeneous. Instead there is a tendency towards a
bubble-like structure with large empty spaces surrounded by thin
"filaments" of galaxies. Even still, the standard model which requires
dark energy ignores these differences. So, Wiltshire's contribution is
to replace the standard assumptions with this "bubble" model, re-solve
the GR equations, and get new equations for the evolution of universe
based on it's *observed structure*, not some simplified model. In his
new equations, dark energy is completely unnecessary. Since the
structure of these "bubbles" is so large, fits to the data with
Wiltshire's model are statistically just as good (actually
indistinguishable) as the standard model, though as a caveat not all
of the calculations have been done. Not only is Wiltshire's model much
better from an Occam's Razor standpoint, it may actually solve some
mysteries which the standard model cannot explain.

I really can't go any further and still call this a "condensed"
version with a straight face. In /. articles in other fields, I enjoy
reading the commentary from experts, so here's an attempt to
reciprocate. Hope this helped."

So, this seems to be the second nail in the coffin of dark stuff. The
first was the elimination of dark matter from apparent anomalies in
galactic rotation, again due to more detailed consideration of GR:

http://arxiv.org/abs/astro-ph/0507619

So, is there any dry powder left in the dark matter/energy keg? Is it
all, perhaps, just GR working according to early 20th century physics
all along.

Enjoy
Roland