Topology of the universe

An interesting article:

http://www.nytimes.com/2003/10/09/science/09COSM.htm

Does anyone know the real story, or have links to original documents? I
have seen to many garbled newspaper stories.

For a start, the headline "Cosmic Soccer Ball? Theory Already Takes Sharp
Kicks" is bad. I gather that what they really mean is one of those
3-manifolds you get by gluing together faces of a dodecahedron. The message
that 90% of the audience take home is "round", which is exactly wrong.
Another 9% wants to know what is outside of the "ball". I know this because
I have already seen some layman's comments.

In any case, one group claims to have ruled out what the other claims to
detect, and both agree the correct answer can be mined from existing WMAP
data. I also get the impression that the evidence for non-trivial topology
comes from the very lowest spherical harmonics (like quadrapole), which
seems sort of dicey to me.

Ralph Hartley

[Mod. note: try http://arxiv.org/abs/astro-ph/0310253 ? -- mjh]

In message , Ralph Hartley
writes
An interesting article:

http://www.nytimes.com/2003/10/09/science/09COSM.htm

Does anyone know the real story, or have links to original documents? I
have seen to many garbled newspaper stories.


In any case, one group claims to have ruled out what the other claims to
detect, and both agree the correct answer can be mined from existing WMAP
data. I also get the impression that the evidence for non-trivial topology
comes from the very lowest spherical harmonics (like quadrapole), which
seems sort of dicey to me.

It's the cover story in the current issue of Nature, about the paper

Dodecahedral space topology as an explanation for weak wide-angle
temperature correlations in the cosmic microwave background 593
JEAN-PIERRE LUMINET, JEFFREY R. WEEKS, ALAIN RIAZUELO, ROLAND LEHOUCQ &
JEAN-PHILIPPE UZAN
doi:10.1038/nature01944

The current 'standard model' of cosmology posits an infinite flat
universe forever expanding under the pressure of dark energy. First-year
data from the Wilkinson Microwave Anisotropy Probe (WMAP) confirm this
model to spectacular precision on all but the largest scales.
Temperature correlations across the microwave sky match expectations on
angular scales narrower than 60B0 but, contrary to predictions, vanish
on scales wider than 60B0. Several explanations have been proposed. One
natural approach questions the underlying geometry of space - namely,
its curvature and topology. In an infinite flat space, waves from the
Big Bang would fill the universe on all length scales. The observed lack
of temperature correlations on scales beyond 60B0 means that the
broadest waves are missing, perhaps because space itself is not big
enough to support them. Here we present a simple geometrical model of a
finite space - the Poincare dodecahedral space - which accounts for
WMAP's observations with no fine-tuning required. The predicted density
is Omega0 1.013 1, and the model also predicts temperature
correlations in matching circles on the sky.

Nature Vol 425 No 6958 p 593

There's a commentary in News and Views

Cosmology: The shape of the Universe p 566
GEORGE F. R. ELLIS
An analysis of astronomical data suggests not only that the Universe is
finite, but also that it has a specific, rather rigid topology. If
confirmed, this is a major discovery about the nature of the Universe.
doi:10.1038/425566a

You'll need a subscription to read these.

An article in New Scientist says that one group has already looked for
the repeating patterns Luminet at al. say would confirm their theory,
and not found them.

[Mod. note: non-ASCII characters fixed up -- mjh]

In message , Ralph Hartley
writes
An interesting article:

http://www.nytimes.com/2003/10/09/science/09COSM.htm

Does anyone know the real story, or have links to original documents? I
have seen to many garbled newspaper stories.


In any case, one group claims to have ruled out what the other claims to
detect, and both agree the correct answer can be mined from existing WMAP
data. I also get the impression that the evidence for non-trivial topology
comes from the very lowest spherical harmonics (like quadrapole), which
seems sort of dicey to me.

It's the cover story in the current issue of Nature, about the paper

Dodecahedral space topology as an explanation for weak wide-angle
temperature correlations in the cosmic microwave background 593
JEAN-PIERRE LUMINET, JEFFREY R. WEEKS, ALAIN RIAZUELO, ROLAND LEHOUCQ &
JEAN-PHILIPPE UZAN
doi:10.1038/nature01944

The current 'standard model' of cosmology posits an infinite flat
universe forever expanding under the pressure of dark energy. First-year
data from the Wilkinson Microwave Anisotropy Probe (WMAP) confirm this
model to spectacular precision on all but the largest scales.
Temperature correlations across the microwave sky match expectations on
angular scales narrower than 60B0 but, contrary to predictions, vanish
on scales wider than 60B0. Several explanations have been proposed. One
natural approach questions the underlying geometry of space - namely,
its curvature and topology. In an infinite flat space, waves from the
Big Bang would fill the universe on all length scales. The observed lack
of temperature correlations on scales beyond 60B0 means that the
broadest waves are missing, perhaps because space itself is not big
enough to support them. Here we present a simple geometrical model of a
finite space - the Poincare dodecahedral space - which accounts for
WMAP's observations with no fine-tuning required. The predicted density
is Omega0 1.013 1, and the model also predicts temperature
correlations in matching circles on the sky.

Nature Vol 425 No 6958 p 593

There's a commentary in News and Views

Cosmology: The shape of the Universe p 566
GEORGE F. R. ELLIS
An analysis of astronomical data suggests not only that the Universe is
finite, but also that it has a specific, rather rigid topology. If
confirmed, this is a major discovery about the nature of the Universe.
doi:10.1038/425566a

You'll need a subscription to read these.

An article in New Scientist says that one group has already looked for
the repeating patterns Luminet at al. say would confirm their theory,
and not found them.

[Mod. note: non-ASCII characters fixed up -- mjh]